Caramelized Onion Pasta Sauce

Hi! I am writing up this caramelized onion pasta sauce so I have it in one place as I know it will become a staple in my house. The onions are cooked really slowly with garlic and sugar to create a delicious sweet onion mixture.

I then mix it into a creamy sauce with thyme and parmesan to create a luscious and cozy pasta. You could add some cooked bacon or pancetta for a meaty variation or some toasted pine nuts for some crunch.

I have used bowtie pasta (farfalle) for this sauce but any pasta shape will work. For another quick and flavorful sauce, consider my 15-minute brown butter sauce.

Ingredients for the Caramelized Onion Pasta Sauce

This is a really simple list of ingredients. Full ingredient amounts and a detailed method are in the recipe card below.

• Bowtie pasta – I have used bowtie pasta (farfalle) but you can use any shape you like, fresh or dried.
• Onions – I have used white onions but you could use red onions. They are thinly sliced and cooked slowly to create a sweet and delicious flavor.
• Butter – I like to use a combination of butter and olive oil to caramelize the onions.
• Olive oil – use a good quality extra virgin olive oil.
• Sugar – I add a touch of sugar to the onions to help them caramelize. It is only a small amount, you could add more if you like.
• Garlic – I use four garlic cloves, you could use less if you like.
• Cream – I use heavy cream in my pasta sauces. It is called single cream in the UK.
• Vegetable broth – I like to add a touch of broth to the cream as it lightens it up. You could use chicken broth if you prefer.
• Parmesan cheese – Use the fine side of a box grater to grate it or use a microplane. Pre grated parmesan is often full of additives so not a good option.
• Thyme – I love the flavor fresh thyme leaves add to this sauce. Dried thyme is great too.
• Fresh parsley – This is optional but it is nice to have a sprinkling of fresh herbs on top.

How to make caramelized onion pasta sauce

The first step is to cook the onions. It is a little time consuming but so worth it! The rest of the sauce comes together very quickly so you could even cook the onions ahead of time. If you’re looking for a lighter, tangier alternative to traditional cream-based sauces, you might also enjoy my tomato goat cheese pasta sauce.

ONE: Heat the butter and olive oil over a medium heat in a large skillet. Add the onions and cook, stirring often for 5 minutes. Add the garlic and sugar and continue to cook on a medium-low heat for 20 – 30 mins. You want them to be a golden brown color.

TWO: Turn the heat up and add the vegetable broth to the pan, it should sizzle and bubble immediately.

THREE: Add the cream and thyme and bring to a very gentle simmer, then lower the heat. If you love herb-forward flavors, you might also like my pesto sauce recipe for pasta which is packed with freshness and comes together quickly.

FOUR: Add the parmesan in a couple of lots, mixing well and letting it melt in between each addition. Season with salt and black pepper to taste.

FIVE: Add your cooked pasta straight into the creamy sauce with ¼ cup of the starchy pasta water.

SIX: Let it gently bubble away for a minute or two, stirring well so the sauce emulsifies and thickens slightly.

Cooking tips for the best results

• Timing! Timing your pasta and sauce to be ready at the same time is the trickiest part of cooking any pasta dish. If you are using dried pasta then start cooking it once you add the cream to the onion mixture. For fresh pasta, start cooking it when you add the parmesan.
• Salting your pasta water. This is a really important step. Your pasta water should be well seasoned. I use about a tablespoon of kosher salt for every 4 cups of water.
• Use a large fry pan. Make sure you use a large skillet when making the sauce so you can add the cooked pasta straight in.
• Don’t have your heat too high. When making a creamy sauce you want to keep the heat quite low. You don’t want the cream to boil, just a very gentle simmer.

Caramelized Onion Pasta Sauce Recipe FAQs

Want some other pasta recipes to try?

If you loved this caramelized onion pasta sauce then make sure you check out my recipe section for lots of other delicious recipes. Looking for another easy tomato-based sauce? My sweet potato tomato sauce is a great option.

Recipe

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Caramelized Onion Pasta Sauce

A delicious and simple caramelized onion pasta sauce, perfect for any night of the week. Onions are slow cooked for flavor then mixed into a creamy sauce. For a lighter option, you might also enjoy my creamy ditalini pasta salad.

Author Minela D’Amore

Course Vegan, Vegetarian

Cuisine Italian Inspired

Keyword caramelized onion pasta sauce, caramelized onions, pasta, pasta sauce

Prep Time 10 minutes minutes

Cook Time 40 minutes minutes

Total Time 50 minutes minutes

Servings 4 people

Calories 774kcal

Ingredients

• 12 ounces bowtie pasta or any other small pasta
• 2 large onions thinly sliced
• 4 cloves garlic minced
• ½ cup vegetable broth
• 1 tablespoon butter
• 3 tablespoons olive oil
• 1 teaspoon sugar
• 1 cup heavy cream
• 1 cup Parmesan cheese grated
• 1 teaspoon dried thyme or 1 tablespoon fresh thyme leaves
• salt and pepper to taste
• fresh parsley chopped (for garnish)

Instructions

• Heat the olive oil and butter in a large fry pan over a medium heat.
• Add the onions and cook, stirring often for 5 minutes.
• Add the sugar and garlic and continue cooking over a medium heat for 20 – 30 mins, stirring often.
• Every stove top is different so adjust the heat if you need to. You want them to cook down into a golden brown color, not blackened.
• Turn the heat up to high and add the vegetable broth, it should sizzle and bubble immediately.
• Add the cream and thyme and bring to a very gentle simmer.
• Add the parmesan in a couple of lots, mixing well and letting it melt in between each addition. Season with salt and pepper to taste.
• Add your cooked pasta straight into the creamy sauce with ¼ cup of the starchy pasta water.
• Let it gently bubble away for a minute or two, stirring well so the sauce emulsifies and thickens slightly.
• Serve with fresh parsley and extra parmesan if you wish. If you're feeling adventurous, you could even make your own pasta with tips from my easy homemade pappardelle.

Notes

Timing: Timing your pasta and sauce to be ready at the same time is the trickiest part of cooking any pasta dish. If you are using dried pasta then start cooking it once you add the cream to the onion mixture. For fresh pasta, start cooking it when you add the parmesan.

Salting your pasta water: This is a really important step. Your pasta water should be well seasoned. I use about a tablespoon of kosher salt for every 4 cups of water.

Use a large fry pan: Make sure you use a large skillet when making the sauce so you can add the cooked pasta straight in.

Don’t have your heat too high: When making a creamy sauce you want to keep the heat quite low. You don’t want the cream to boil, just a very gentle simmer.