# What You’ll Need:
→ Pasta
01 - 12 ounces rigatoni or penne
→ Onions & aromatics
02 - 3 large yellow onions, thinly sliced
03 - 2 tablespoons unsalted butter
04 - 1 tablespoon olive oil
05 - 1/2 teaspoon fine salt
06 - 1/4 teaspoon freshly ground black pepper
07 - 1 teaspoon granulated sugar
08 - 2 garlic cloves, minced
09 - 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried)
→ Sauce & assembly
10 - 1/2 cup dry white wine
11 - 2 cups vegetable broth
12 - 2 teaspoons Worcestershire sauce
13 - 1 tablespoon all-purpose flour
14 - 1 cup heavy cream
15 - 1 1/2 cups grated Gruyère, divided
16 - 1/2 cup grated Parmesan
17 - 1 tablespoon chopped fresh parsley (for garnish)
# Directions:
01 - Preheat the oven to 400°F and lightly grease a 9x13-inch baking dish.
02 - Bring a large pot of salted water to a rolling boil, cook the pasta until just shy of al dente, drain and reserve.
03 - In a large skillet over medium heat, melt the butter with the olive oil. Add the sliced onions, salt, pepper and sugar, and cook, stirring frequently, until the onions are deeply golden and caramelized, about 25 to 30 minutes.
04 - Stir in the garlic and thyme and cook briefly until fragrant, about 1 minute. Sprinkle the flour over the onions, cook 1 minute more, then pour in the white wine, scraping up any browned bits; simmer 2 minutes.
05 - Add the vegetable broth and Worcestershire sauce, bring to a simmer and cook 2 to 3 minutes. Reduce heat to low, stir in the cream and 1 cup of the Gruyère until the cheese melts and the sauce is smooth.
06 - Fold the drained pasta and the grated Parmesan into the onion–cream mixture until evenly coated.
07 - Transfer the pasta mixture to the prepared baking dish, sprinkle the remaining 1/2 cup Gruyère evenly over the top, and bake until bubbly and golden, 20 to 25 minutes.
08 - Remove from the oven, let rest briefly, garnish with chopped parsley and serve warm.
