# What You'll 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
# Directions:
01 - Preheat oven to 400°F. Lightly grease a baking dish measuring approximately 8x12 inches. Cook pasta in salted boiling water for 2 minutes less than package instructions. Drain and set aside.
02 - 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 fully caramelized.
03 - Add minced garlic and thyme to the caramelized onions. Cook for 1 minute until fragrant.
04 - Pour in dry white wine while scraping the bottom of the skillet to deglaze. Cook until wine reduces by half, approximately 3 minutes.
05 - Stir in broth and Worcestershire sauce. Simmer for 5 minutes. Season with freshly ground black pepper to taste.
06 - Reduce heat to low. Stir in heavy cream and immediately remove from heat.
07 - Combine cooked pasta, caramelized onion mixture, Gruyère cheese, mozzarella cheese, and Parmesan cheese in a large bowl. Mix thoroughly until evenly combined.
08 - Pour mixture into prepared baking dish. Sprinkle remaining Gruyère cheese evenly over the top.
09 - Bake for 15 to 20 minutes until golden brown and bubbling at the edges.
10 - Allow dish to rest for 5 minutes. Garnish with chopped fresh parsley before serving if desired.