Description

This Caramelized Onion Pasta is a rich and flavorful dish featuring slowly caramelized sweet onions, garlic, and a generous amount of Parmesan cheese that forms a glossy, indulgent sauce coating tender linguine. With a hint of fresh lemon juice and parsley, this simple yet elegant pasta is perfect for a comforting dinner for two.

Ingredients

Scale

For the Onion Mixture

2 Tbsp. extra-virgin olive oil
2 Tbsp. unsalted butter
2 lb. sweet or yellow onions (about 4 large), thinly sliced
1 1/2 tsp. kosher salt, plus more to taste
4 garlic cloves, finely chopped
Freshly ground black pepper, to taste

For the Pasta

8 oz. linguine or other long strand pasta
4 oz. Parmesan, finely grated (about 2 cups), plus more for serving
½ lemon (juice only)
½ cup finely chopped parsley

Instructions

Caramelize the Onions: Heat 2 tablespoons of olive oil and 2 tablespoons of unsalted butter in a medium Dutch oven or heavy pot over medium heat until the butter melts. Add the thinly sliced onions, a large pinch of kosher salt, and freshly ground black pepper. Cook the onions, stirring occasionally, until they become very tender and attain a deep golden brown color, about 30 minutes. Then stir in the finely chopped garlic cloves and cook for about 1 minute until fragrant.
Cook the Pasta: While the onions are caramelizing, bring a large pot of salted water to a boil. Cook 8 ounces of linguine or your preferred long pasta, stirring occasionally, until it is very al dente—about 2 minutes less than the package instructions recommend. Drain the pasta, reserving 1½ cups of the pasta cooking water.
Combine Pasta and Onion Mixture: Add the drained pasta and 1 cup of the reserved pasta water to the pot with the caramelized onions. Stir to combine. Gradually add small handfuls of the grated Parmesan cheese, stirring each time until melted. Continue to add cheese and pasta water as needed until a glossy sauce forms that coats the pasta evenly.
Finish and Serve: Squeeze the juice of half a lemon into the pasta and stir in the finely chopped parsley. Taste and adjust seasoning with additional black pepper and salt if needed. Divide the pasta into shallow bowls, topping each serving with extra Parmesan cheese and black pepper before serving.

Notes

The onion and garlic mixture can be prepared up to 5 days in advance; store covered in the refrigerator or freeze for up to 3 months.
Be patient while caramelizing the onions for the best deep, sweet flavor—this step is crucial to the dish.
Adjust pasta water amounts to achieve the perfect sauce consistency.
Use freshly grated Parmesan for the best melt and flavor.
Pair this pasta with a simple green salad and crusty bread for a complete meal.

Prep Time: 15 minutes
Cook Time: 45 minutes
Category: Main Course
Method: Stovetop
Cuisine: Italian

Keywords: caramelized onion pasta, caramelized onions, easy pasta recipe, vegetarian pasta, Parmesan pasta, comfort food