Description
This French Onion Mac and Cheese recipe combines the rich, caramelized flavors of sweet onions with creamy Gruyère and Parmesan cheeses to create a decadent twist on a classic comfort dish. Baked to golden perfection with a crispy panko breadcrumb topping, it’s a perfect crowd-pleaser for family dinners or special gatherings.
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 total)
Cheese Sauce
- 6 tablespoons salted butter (divided: 2 tablespoons for onions, 3 tablespoons for sauce, 1 tablespoon for topping)
- 3 tablespoons all-purpose flour
- 2 ½ cups whole milk
- 1 ½ teaspoons salt (remaining)
- ½ teaspoon black pepper
- 1 teaspoon dried rosemary
- 1 teaspoon dried thyme
- 3 cups freshly shredded Gruyère cheese
- 1 cup grated Parmesan cheese
Topping
- ½ cup panko breadcrumbs
- ¼ teaspoon salt
- Fresh thyme (optional, for garnish)
Instructions
- Preheat oven: Preheat your oven to 400°F to have it ready for baking the assembled mac and cheese later.
- Caramelize the onions: In a large oven-safe skillet, heat 2 tablespoons of butter and 1 tablespoon of olive oil over medium heat. Add the thinly sliced sweet onions and cook for 25-30 minutes, stirring occasionally, until they are golden brown and caramelized.
- Thicken the sauce: Add minced garlic to the caramelized onions and cook for about 30 seconds until fragrant. Stir in beef broth, ¾ teaspoon of salt, Worcestershire sauce, balsamic vinegar, and brown sugar. Simmer the mixture for 5-10 minutes until it reduces and most of the liquid evaporates. Set aside ¾ cup of the caramelized onions for topping.
- Cook the pasta: While onions cook, bring a large pot of salted water (with 2 teaspoons salt) to a boil. Add pasta and cook until just shy of al dente (about 1-2 minutes less than package instructions). Drain and set aside.
- Make the cheese sauce: In a separate skillet or Dutch oven, melt 3 tablespoons of butter over medium heat. Whisk in flour and cook for 1-2 minutes to form a roux. Gradually whisk in milk, about ½ cup at a time, continually stirring until the sauce thickens. Reduce heat to low and add remaining salt, pepper, dried thyme, rosemary, Gruyère, and Parmesan cheeses. Stir until smooth and creamy.
- Prepare the breadcrumb topping: Melt the remaining 1 tablespoon butter in a small bowl and combine with panko breadcrumbs and ¼ teaspoon salt until mixed well.
- Combine pasta and sauce: Add the cooked pasta and cheese sauce to the oven-safe skillet with the caramelized onions. Stir thoroughly to coat the pasta with the cheese-onion mixture evenly.
- Add toppings: Spread the reserved caramelized onions evenly over the pasta mixture, then sprinkle the panko breadcrumb topping evenly on top.
- Bake: Place the skillet in the preheated oven and bake for 12-15 minutes until the topping is golden and bubbly.
- Broil for extra crispiness: For an extra crispy crust, broil the mac and cheese for a few minutes until browned to your liking. Garnish with fresh thyme if desired and serve warm.
Notes
- You can substitute beef broth with vegetable or chicken broth if preferred, but beef adds a richer flavor.
- Be careful not to overcook the pasta initially, as it will finish cooking in the oven sauce.
- Gruyère cheese is key for that authentic French onion flavor, but you can mix with other melting cheeses if needed.
- Use fresh thyme as a aromatic garnish to enhance the dish’s flavor.
- Leftover French Onion Mac and Cheese can be refrigerated for up to 3 days and reheated in the oven for best texture.
