Creamy Caramelized Onion Pasta
This creamy caramelized onion pasta is rich, silky and full of flavor. Sweet, jammy onions are tossed through a garlic parmesan cream sauce with thyme and a squeeze of lemon to balance.
Servings: 2 people
Ingredients
- 200 grams dried pasta (or 300 grams fresh)
For the onions
- 1 tablespoon olive oil
- 1 tablespoon butter
- 2 medium onions (mine weighed 450 grams total)
For the sauce
- 1 tablespoon butter
- 2 garlic cloves, minced
- ¼ teaspoon red pepper flakes (optional)
- ⅔ cup heavy cream
- 50 grams parmesan cheese, very finely grated
- 1 tablespoon fresh thyme leaves, roughly chopped
- 1 tablespoon lemon juice, plus zest to serve
- salt and pepper to taste
Instructions
Caramelize the onions
- Trim both ends off the onions then cut in half lengthways, peel, then lay each half flat and slice into ¼-inch thick half circles
- Heat 1 tablespoon of olive oil and 1 tablespoon of butter in a heavy bottomed skillet or Dutch oven over a medium heat and cook the onions for 10 minutes until softened.
- Mix the salt through then lower the heat down to low and continue cooking for 40 minutes until golden and super soft. It needs to be stirred often so they don't catch and burn.
- Add a small splash of water if they are getting too dry. Set aside when done.
Cook the pasta
- Boil your pasta in well salted boiling water, I usually undercook by 1 min from package instructions. Reserve a cup of pasta water before draining.
Make the sauce
- When the pasta only has about 5 minutes to go return the skillet you cooked the onions in to medium heat. Add the garlic (and red pepper flakes if using) and cook gently for 1 minute until fragrant, it shouldn’t brown at all.
- Pour in the cream and bring to a very gentle simmer, lowering the heat if needed so it never boils. Stir in the thyme.
- Add the parmesan in 2-3 additions, mixing well and letting it melt between each addition until the sauce is smooth.
- Add the cooked pasta, caramelized onions, lemon juice and ¼ cup pasta water and toss well.
- Let it gently bubble away for a minute or two over a low heat so the pasta finishes cooking and the sauce thickens, adding more pasta water if needed to loosen. It will thicken quickly off the heat so keep it on the saucy side in pan.
- Check for seasoning and serve immediately with extra parmesan and grated lemon zest if desired.
Video
Notes
Onions - It might seem like a lot but they cook down significantly. Take your time here, properly caramelized onions should be deeply golden, soft and jammy, not just softened.
Timing - Caramelizing onions takes time and can vary depending on your pan and heat. Focus on the color and texture rather than the exact time. You can get the pasta boiling when they look close to being done.
Pasta water - Don’t skip this! It helps loosen the sauce and creates a silky, glossy finish. Add more as needed to get the right consistency. Creamy sauces thicken quickly off the heat so you want it slightly saucier than you think in the pan.
Parmesan - Finely grate your own using a microplane or the star side of a box grater so it melts smoothly into the sauce.
Lemon juice - Added at the end to balance the richness of the sauce and lift the sweetness of the onions. Adjust to taste.
Thyme - Adds a subtle savory note that balances the sweetness of the onions. You can leave it out if you prefer.