Description
A comforting and flavorful caramelized onion pasta recipe featuring slow-cooked sweet onions, garlic, and Parmesan cheese tossed with spaghetti for a creamy and satisfying Italian-inspired main course.
Ingredients
Scale
For the Pasta and Sauce
- 12 oz spaghetti or fettuccine
- 3 large yellow onions, thinly sliced
- 3 tbsp unsalted butter
- 1 tbsp olive oil
- 1 tsp salt
- ½ tsp black pepper
- ¼ tsp red pepper flakes (optional)
- 2 cloves garlic, minced
- ½ cup grated Parmesan cheese
- ½ cup reserved pasta water
- 1 tsp fresh thyme leaves or ½ tsp dried thyme
For Garnish
- Extra Parmesan cheese
- Chopped parsley
Instructions
- Cook the Pasta: Bring a large pot of salted water to a boil. Add the spaghetti or fettuccine and cook according to package directions until al dente. Reserve ½ cup of the pasta cooking water, then drain the pasta and set aside.
- Caramelize the Onions: In a large skillet over medium-low heat, melt the unsalted butter with olive oil. Add the thinly sliced onions and cook slowly, stirring often, for 25–30 minutes until the onions are deeply golden and caramelized. If the onions start to dry out, add a splash of water to deglaze the pan and prevent burning.
- Add Garlic and Seasonings: Stir in the minced garlic, fresh or dried thyme, salt, black pepper, and red pepper flakes if using. Cook for an additional 2–3 minutes to let the flavors meld and the garlic soften.
- Toss Pasta with Sauce: Add the cooked pasta directly to the skillet with the caramelized onions. Pour in the reserved pasta water and sprinkle the grated Parmesan cheese over the top. Toss everything together until the pasta is fully coated, glossy, and heated through.
- Serve: Plate the pasta warm and garnish with extra Parmesan cheese and a sprinkle of chopped parsley for color and freshness.
Notes
- For extra richness, stir in a splash of cream or a spoonful of mascarpone cheese just before serving.
- This dish pairs beautifully with a crisp side salad or crusty bread.
- Add heartiness by mixing in sautéed mushrooms or crispy pancetta.
