Description
This French Onion Mac and Cheese recipe combines rich, caramelized onions with creamy Gruyere cheese sauce and perfectly cooked cavatappi pasta, topped with a crispy panko breadcrumb crust. A comforting and savory twist on classic mac and cheese, baked to bubbly perfection.
Ingredients
Scale
Caramelized Onions:
- 4 tablespoons unsalted butter – divided
- 4 large yellow onions – peeled and sliced
- 2 tablespoons balsamic vinegar
- 2 teaspoons fresh thyme leaves
- A splash of beef broth or water – only if needed
Mac and Cheese:
- 1 pound cavatappi pasta
- ½ cup unsalted butter
- ⅓ cup all-purpose flour
- 4 cups whole milk – plus more as needed
- 16 ounces freshly shredded Gruyere cheese – divided (about 4 cups)
- 1 teaspoon Dijon mustard
- 1 teaspoon garlic powder – or to taste
- Salt and pepper – to taste
Panko Breadcrumb Topping:
- ⅓ cup panko breadcrumbs
- 3 tablespoons olive oil
Instructions
- Caramelize Onions: In a large deep pan, melt 2 tablespoons of butter over medium heat. Add sliced onions and a pinch of salt. Cook over medium heat for 15 minutes to start the caramelization. Reduce heat to medium-low and continue cooking, stirring occasionally, until onions are deep golden and caramelized, about 30 more minutes. If needed, add a splash of broth or water to deglaze the pan. During the last 5 minutes, add remaining 2 tablespoons butter, balsamic vinegar, and thyme leaves. Stir until golden and set aside.
- Prepare Pasta: Preheat oven to 375 degrees F. Cook cavatappi pasta according to package instructions until just al dente. Drain and rinse with cold water to stop cooking. Set aside.
- Make Cheese Sauce: In a large pot, melt ½ cup butter over medium heat. Whisk in flour and cook for 2-3 minutes until roux smells nutty. Gradually add milk, whisking to avoid lumps; sauce will thicken as it heats. Season with Dijon mustard, garlic powder, salt, and pepper. Over low heat, stir in 3 cups shredded Gruyere until melted and smooth. Turn off heat.
- Combine Pasta and Sauce: Add cooked pasta to the cheese sauce and stir to coat evenly.
- Assemble Mac and Cheese: Toss panko breadcrumbs with olive oil and set aside. In a 9×13 baking dish, spread half the mac and cheese. Swirl in most caramelized onions and ¾ cup of the remaining shredded Gruyere. Layer remaining mac and cheese on top. Sprinkle with remaining onions, cheese, and panko topping.
- Bake: Place the baking dish on a sheet pan to catch spills. Bake uncovered at 375 degrees F for 25 minutes or until bubbly and golden. Let cool slightly before serving.
Notes
- Cook pasta until just al dente to avoid overcooking after baking.
- Use yellow onions for their mild sweetness and best caramelization results.
- Use a large 12-inch deep pan for onions to prevent overcrowding and steaming.
- Patience is important for caramelized onions; cook low and slow for 40-45 minutes total.
- Grate your own Gruyere cheese to avoid anti-caking agents that can affect sauce texture.
- Caramelized onions can be made up to 2 days ahead and refrigerated.
- Assemble the mac and cheese without the panko topping the night before for easy preparation.
- Freeze assembled mac and cheese (cooled) for up to 2 months; thaw overnight in fridge before reheating.
- Reheat with a splash of milk to maintain creamy texture.
- Substitute Gruyere with Swiss, gouda, or white cheddar if desired.
- Try pasta varieties like shells, fusilli, or rigatoni as alternatives.
