Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper if using.

In a large skillet, heat olive oil over medium heat. Add sliced onions, stirring to coat them in oil.

Cook onions for about 15-20 minutes until golden brown and caramelized.

While the onions are caramelizing, bring a pot of salted water to a boil and cook pasta according to package instructions.

Once cooked, reserve a cup of pasta water, drain the pasta and set aside.

Add the drained pasta to the skillet with caramelized onions and mix well, adding reserved pasta water as needed.

Season with salt and pepper, add fresh herbs if desired, and cook for another minute before serving.