Easy Instant Pot Lemon Spaghetti Recipe

I love pasta, which probably isn’t much of a surprise if you’ve spent any time looking through my recipes, but sometimes I want something a little different from the usual tomato sauce or cheesy pasta bake. This Instant Pot lemon spaghetti is a lovely option when you fancy something creamy, with plenty of garlic and a fresh lemon flavour, without having to stand over a saucepan for ages.

It’s made with spaghetti, lemon, garlic, shallot, Parmesan, milk and stock, and the clever bit is that the spaghetti cooks directly in the Instant Pot rather than needing a separate pan of boiling water. You add the milk and cheese afterwards to make the sauce, so there’s no need to cook those under pressure.

I particularly like the idea of having fewer pans to wash up because, while I enjoy cooking, I can’t say I’ve ever finished dinner and thought how much I’d love to spend the next half an hour washing saucepans!

If you’ve got an Instant Pot sitting in the cupboard and tend to use it for the same few meals, this is another recipe to add to your collection.

Why make lemon spaghetti in the Instant Pot?

The biggest advantage of using an Instant Pot for spaghetti is that you don’t need to boil the pasta separately and then prepare the sauce in another pan.

Instead, the spaghetti cooks in stock with garlic, shallot, butter and lemon juice. Once the pressure cooking is finished, you stir in the milk and Parmesan and give everything a few minutes to come together.

The result is intended to be a creamy lemon pasta with plenty of flavour, without requiring lots of complicated ingredients.

It’s worth remembering that pressure cooking isn’t necessarily instantaneous, despite the name. The appliance needs time to come up to pressure, and there are a few minutes of finishing time afterwards, so this is still a proper dinner rather than something that’s ready in five minutes.

Ingredients for Instant Pot lemon spaghetti

This recipe makes four portions.

You’ll need:

• 225g spaghetti
• 350ml chicken or vegetable stock
• 2 cloves garlic, minced
• 1 shallot, thinly sliced
• 120g Parmesan cheese, shredded or shaved
• 250ml semi-skimmed milk
• 1 lemon
• 1 tsp butter or olive oil
• 1 tbsp butter

You don’t need an enormous shopping list for this recipe, which is one of the things I like about simple pasta dishes. Most of the flavour comes from the lemon, garlic, shallot and cheese rather than lots of different herbs and spices.

As I’m vegetarian, I’d use vegetable stock and a vegetarian hard cheese alternative instead of traditional Parmesan. If you’re cooking for someone who eats meat, chicken stock is another option included in the original recipe.

How to make lemon spaghetti in the Instant Pot

Start by switching your Instant Pot to the sauté setting.

Once it’s hot, add the teaspoon of butter or olive oil and the sliced shallot, then cook for around two minutes.

Add the minced garlic, switch off the sauté function and leave it for approximately one minute. Stir the bottom of the pot to loosen anything that might have stuck during cooking.

Pour in the stock and stir again, making sure there are no browned bits stuck to the bottom.

Add the spaghetti to the pot. You can break it in half, or even into thirds if you prefer, which may make it easier to fit inside the appliance.

Use a spoon to gently push the spaghetti into the stock without stirring everything together. The original method calls for the spaghetti to be submerged, so check that it fits appropriately in your particular Instant Pot.

Add the tablespoon of butter over the spaghetti, followed by the juice from half the lemon.

Secure the lid, make sure the pressure valve is in the sealing position and select the manual pressure cooking setting for five minutes.

The Instant Pot will need time to come up to pressure before the five-minute cooking period begins. The original recipe suggests this takes approximately ten minutes, although it can vary between appliances.

When the cooking time finishes, carefully use the quick-release method, following the safety instructions for your appliance. Keep your hands and face away from the escaping steam.

Once the pressure has fully released and the lid can be opened safely, add the semi-skimmed milk and Parmesan cheese.

Stir everything together, then replace the lid without starting another pressure-cooking cycle. Leave it to rest for approximately four to five minutes so the cheese can melt and the sauce can thicken.

Finally, squeeze in the juice from the remaining half of the lemon, toss everything together and serve.

What does lemon spaghetti taste like?

Lemon spaghetti has a creamy, savoury flavour with a fresh citrus finish.

The Parmesan provides a salty, cheesy flavour, while the garlic and shallot add depth. The lemon helps balance the richness of the milk, butter and cheese.

I think lemon is particularly good with pasta because it adds flavour without needing lots of different ingredients. It also makes a nice change if you’ve had several tomato-based pasta dinners recently and fancy something different.

This isn’t intended to be a spicy dish, so it’s a good option if you’re looking for a pasta recipe without chilli.

Why use stock instead of water?

The spaghetti cooks directly in the stock, which adds flavour as the pasta absorbs the liquid.

The original recipe allows either chicken or vegetable stock, so you can choose whichever suits your preferences and dietary requirements.

I’d be mindful of the salt content, particularly because Parmesan is already quite salty. It’s easier to add a little seasoning at the end than to rescue a sauce that’s become too salty.

The measured recipe uses 350ml stock, so I’d follow that quantity if you’re making the original version rather than adding extra water without considering how it could affect the sauce.

Can I make this Instant Pot lemon spaghetti vegetarian?

Yes, with a couple of ingredient choices.

Use vegetable stock instead of chicken stock and choose a vegetarian hard cheese instead of traditional Parmesan, which is generally made using animal rennet.

That way, you can keep the intended cheesy flavour without using ingredients that aren’t suitable for vegetarians.

If you’re vegetarian like me, it’s worth checking cheese labels because Parmesan is one of those ingredients that appears in an awful lot of recipes described as vegetarian, even though traditional Parmesan itself isn’t.

Can I make lemon spaghetti without milk?

The original recipe uses 250ml semi-skimmed milk, which is added after pressure cooking to help make the sauce creamy.

You could experiment with alternatives, but I wouldn’t promise identical results because different products behave differently when heated and mixed with cheese and lemon juice.

If you need a dairy-free version, you’d need to replace the milk, Parmesan and butter with suitable alternatives rather than simply swapping the butter for olive oil.

That’s quite a significant change to the recipe, so I’d treat it as an experiment rather than a guaranteed substitution.

Can I use a different type of pasta?

The measured recipe was written for 225g spaghetti and a five-minute pressure-cooking time.

Other pasta shapes and thicknesses can need different cooking times and amounts of liquid, so I wouldn’t automatically substitute penne, fusilli or another shape and expect exactly the same result.

If you’ve got a packet of spaghetti in the cupboard, that’s what I’d recommend using for the first attempt.

My how to cook pasta guide has more general advice about getting pasta just right, although pressure cooking is a little different from boiling it in a saucepan.

Can I use gluten-free spaghetti?

You could experiment with gluten-free spaghetti, but I wouldn’t use the same pressure-cooking instructions without checking whether they’re suitable for that particular product.

Gluten-free pasta can soften or break apart differently from traditional wheat pasta, particularly when it’s cooked under pressure.

If you’re cooking for someone with coeliac disease, remember to check the stock, cheese and other packaged ingredients as well.

You might find my gluten-free pasta cooking tips useful if you’re getting used to cooking with alternatives.

Why add the milk and Parmesan after pressure cooking?

The original method adds the milk and cheese after the spaghetti has finished pressure cooking.

That means you can stir them into the hot pasta and give the sauce a few minutes to thicken without subjecting the dairy ingredients to the pressure-cooking stage.

I think that’s a useful detail because milk-based sauces can be a little temperamental, particularly when you’re also using lemon.

The recipe finishes with the remaining lemon juice after the sauce has rested, rather than adding all the lemon at once.

How do I stop spaghetti sticking in the Instant Pot?

The original method recommends pushing the spaghetti into the stock without stirring it after adding it to the pot.

It’s also important to deglaze the bottom properly after cooking the shallot and garlic, because stuck-on ingredients can trigger a burn warning in some pressure cookers.

Different Instant Pot models and spaghetti brands can behave differently, so always follow your appliance’s minimum-liquid and safe-use instructions.

If you find your spaghetti sticks together or doesn’t cook evenly, make a note of the pasta brand and appliance you used before trying again. That will make it easier to work out whether anything needs adjusting.

Is lemon spaghetti healthy?

This recipe contains pasta, milk, cheese, lemon, garlic, shallot and butter, so it provides carbohydrates along with some protein and fat.

I wouldn’t describe it as a particularly low-fat pasta dish because it contains 120g Parmesan and additional butter, but that doesn’t mean you can’t enjoy it as part of a balanced diet.

I’ve written before about how my attitude towards food has changed since losing weight, and I don’t think every meal needs to be made as low in calories as possible to deserve a place on the menu.

Sometimes you fancy a creamy pasta dish, and that’s absolutely fine. You can always serve it with vegetables or a salad if you’d like a little more variety on your plate.

For more on this, have a look at my article about whether pasta is healthy.

What can I serve with lemon spaghetti?

You can serve this spaghetti as a main meal or alongside something else, depending on how hungry everyone is.

Roasted asparagus or courgette would work well with the lemon flavour, as would a simple green salad.

If you’re making dinner for meat eaters, you could serve chicken or prawns alongside it. For a vegetarian meal, you might prefer some extra vegetables or another vegetarian protein source.

Personally, I think the lemon and garlic flavours are enough to make this interesting without adding lots of extras, so I’d keep the side dishes fairly simple.

Can I make Instant Pot lemon spaghetti ahead?

You can prepare it ahead if needed, although creamy pasta is often nicest when freshly made.

The sauce may thicken as the spaghetti cools and absorbs more liquid, so leftovers won’t necessarily have exactly the same texture as the original dish.

If you’re making it for guests or a family meal, I’d aim to serve it shortly after the sauce has finished thickening rather than leaving it sitting around for ages.

How do I store leftover lemon spaghetti?

If you have leftovers, cool them promptly and transfer them to a covered container in the fridge.

Eat them within an appropriate refrigerated storage period and reheat thoroughly until steaming hot throughout.

You may need a small splash of water or stock when reheating because the sauce can become thicker as it cools.

I wouldn’t leave cooked spaghetti sitting out on the worktop for hours, particularly when the recipe contains milk and cheese.

Can I freeze lemon spaghetti?

I wouldn’t particularly recommend freezing this recipe because the creamy sauce and pasta texture may change after defrosting.

It isn’t necessarily impossible, but I’d rather make a smaller quantity or enjoy refrigerated leftovers than deliberately prepare lots for the freezer.

Instant Pot lemon spaghetti FAQs

How long does Instant Pot lemon spaghetti take?

The original recipe gives a total time of approximately 35 minutes, including preparation, pressure cooking, the time needed to reach pressure and finishing the sauce.

How long do I pressure cook the spaghetti?

The original recipe uses five minutes on the manual pressure-cooking setting, followed by a quick pressure release.

Do I need to boil the spaghetti first?

No. The spaghetti cooks directly in the Instant Pot with the stock.

Can I use bottled lemon juice?

Fresh lemon is recommended for the intended flavour, although you could experiment with bottled juice if that’s what you have.

Can I use olive oil instead of butter?

The recipe allows butter or olive oil for the initial sautéing stage. It also uses a separate tablespoon of butter later in the method, so replacing that would be an additional change.

Can I make this without an Instant Pot?

You could make a lemon spaghetti dish on the hob, but this particular recipe is designed around pressure cooking. You would need a different cooking method and potentially different liquid quantities.

More easy pasta recipes

If you love pasta as much as I do, have a look through my pasta recipes for plenty more ideas.

My creamy courgette pasta is another option when you fancy something different from a tomato sauce, while pasta primavera is lovely when you’ve got vegetables to use up.

You might also enjoy my mushroom and spinach pasta bake or tomato pasta sauce if you’re planning a few pasta meals for the week.

And if you’re looking for more ways to make pasta fit into your usual meal planning, my Slimming World pasta recipes collection has lots of inspiration too.

I think the nicest thing about pasta is how many completely different meals you can make from such a simple ingredient. Whether you fancy a cheesy bake, a tomato-based sauce or something fresh and lemony like this, there’s usually a way to make dinner without having to buy half the supermarket first!

If you make this Instant Pot lemon spaghetti, I’d love to know how it turns out in your particular model and whether you’ve tried any different additions.

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