# What You Need:
→ Pasta
01 - 10.5 oz short pasta such as rigatoni or penne
→ Onions
02 - 3 large yellow onions, thinly sliced
03 - 2 tablespoons unsalted butter
04 - 1 tablespoon olive oil
05 - 1/2 teaspoon salt
06 - 1/2 teaspoon sugar
07 - 2 cloves garlic, minced
→ Flavorings
08 - 1 tablespoon fresh thyme leaves or 1 teaspoon dried thyme
09 - 1/2 cup dry white wine
10 - 2 cups low-sodium beef or vegetable broth
11 - 1 tablespoon Worcestershire sauce
12 - Freshly ground black pepper to taste
→ Sauce and Cheese
13 - 1/2 cup heavy cream
14 - 1 cup grated Gruyère cheese
15 - 1/2 cup grated mozzarella cheese
16 - 1/3 cup grated Parmesan cheese
→ Topping
17 - 1/3 cup grated Gruyère cheese
18 - 2 tablespoons chopped fresh parsley, optional
# Steps:
01 - Preheat oven to 400°F. Lightly grease a baking dish approximately 8 by 12 inches.
02 - Cook pasta in salted boiling water for 2 minutes less than package instructions. Drain and set aside.
03 - In a large skillet over medium heat, melt butter with olive oil. Add onions, salt, and sugar. Cook, stirring frequently, for 20 to 25 minutes until deep golden and caramelized.
04 - Add garlic and thyme; cook for 1 minute until fragrant.
05 - Pour in white wine, scraping the bottom to deglaze. Cook until wine reduces by half, about 3 minutes.
06 - Stir in broth and Worcestershire sauce. Simmer for 5 minutes. Season with black pepper.
07 - Reduce heat to low. Stir in heavy cream and remove from heat.
08 - Combine cooked pasta, caramelized onion mixture, Gruyère, mozzarella, and Parmesan in a large bowl. Mix well.
09 - Pour mixture into prepared baking dish. Sprinkle with remaining Gruyère cheese.
10 - Bake for 15 to 20 minutes until golden and bubbling.
11 - Let rest for 5 minutes. Garnish with chopped parsley before serving if desired.
