Description
This French Onion Mac and Cheese combines the rich, caramelized sweetness of slow-cooked onions with a creamy, cheesy sauce made from Gruyère and Parmesan cheeses. Enhanced with aromatic herbs and a crispy breadcrumb topping, this baked dish is a comforting twist on classic mac and cheese, perfect for serving a crowd or a family dinner.
Ingredients
Scale
Pasta
- 1 pound pasta (elbows, cavatappi, or shells)
Caramelized Onions
- 1 ½ pounds sweet onions, thinly sliced (about 2-3 large or 4 medium)
- 2 tablespoons salted butter
- 1 tablespoon olive oil
- 4 garlic cloves, finely minced
- ½ cup beef broth
- 1 tablespoon Worcestershire sauce
- 1 tablespoon balsamic vinegar
- 1 tablespoon packed brown sugar
- ¾ teaspoon salt (from the 2 ½ teaspoons divided)
Cheese Sauce
- 3 tablespoons salted butter
- 3 tablespoons all-purpose flour
- 2 ½ cups whole milk
- 1 ½ teaspoons salt (from the 2 ½ teaspoons divided)
- ½ teaspoon black pepper
- 1 teaspoon dried rosemary
- 1 teaspoon dried thyme
- 3 cups freshly shredded Gruyère cheese
- 1 cup grated Parmesan cheese
Topping
- 1 tablespoon salted butter
- ½ cup panko breadcrumbs
- ¼ teaspoon salt
Garnish (optional)
- Fresh rosemary
- Fresh thyme
Instructions
- Preheat Oven: Preheat your oven to 400℉ to prepare for baking the assembled mac and cheese.
- Caramelize Onions: In a large oven-safe skillet over medium heat, melt 2 tablespoons of butter with 1 tablespoon of olive oil. Add the thinly sliced onions and cook for 25-30 minutes, stirring occasionally until they turn golden brown and caramelized.
- Add Garlic and Simmer: Stir in the minced garlic and cook for 30 seconds until fragrant. Add beef broth, ¾ teaspoon salt, Worcestershire sauce, balsamic vinegar, and brown sugar. Simmer for 5-10 minutes until the liquid reduces and thickens. Set aside ¾ cup of the caramelized onions for the topping.
- Cook Pasta: While onions are cooking, bring a large pot of water with 2 teaspoons salt to a boil. Add the pasta and cook 1-2 minutes less than al dente. Drain and set aside.
- Make Cheese Sauce: In a separate skillet or Dutch oven over medium heat, melt 3 tablespoons of butter. Whisk in flour and cook for 1-2 minutes to form a roux. Gradually whisk in milk ½ cup at a time until thickened. Lower heat and stir in remaining 1 ½ teaspoons salt, black pepper, dried thyme, dried rosemary, Gruyère, and Parmesan until smooth.
- Prepare Topping: In a small bowl, melt remaining 1 tablespoon of butter, then combine with panko breadcrumbs and ¼ teaspoon salt.
- Combine Pasta and Sauce: Add the cooked pasta and cheese sauce to the skillet with the caramelized onions and stir well to coat the pasta evenly. Spread the reserved onions over the top, then sprinkle evenly with the panko breadcrumb mixture.
- Bake: Place the skillet in the preheated oven and bake for 12-15 minutes until the top is golden and bubbly. For an extra crispy topping, place under the broiler for a few minutes. Garnish with fresh rosemary and thyme if desired before serving.
Notes
- Use an oven-safe skillet to avoid transferring the mac and cheese to another dish before baking.
- Cooking onions low and slow ensures deep caramelization and rich flavor.
- Cooking pasta slightly less than al dente prevents it from becoming mushy when baked.
- You can substitute beef broth with vegetable broth for a lighter flavor.
- Fresh herbs can be added to the cheese sauce for more aromatic layers if preferred.
