Description
French Onion Mac and Cheese combines rich caramelized onions, creamy Gruyere cheese sauce, and perfectly cooked cavatappi pasta topped with crispy panko breadcrumbs. This decadent baked casserole delivers the comforting flavors of classic French onion soup in a hearty mac and cheese.
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 the sliced onions and a pinch of salt. Cook for 15 minutes stirring occasionally. Reduce heat to medium-low and cook the onions for another 30 minutes, stirring occasionally, until deeply golden and caramelized. If needed, add a splash of beef broth or water to deglaze. In the last 5 minutes, add the remaining 2 tablespoons butter, balsamic vinegar, and thyme leaves to finish the caramelization. Set aside.
- Preheat Oven and Prepare Pasta: Preheat the oven to 375 degrees F. Cook the cavatappi pasta according to package directions 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 the flour and cook for 2-3 minutes until the mixture smells nutty and forms a roux. Gradually whisk in the milk, stirring continuously to avoid lumps, until the sauce thickens. Season with Dijon mustard, garlic powder, salt, and pepper. Stir in 3 cups of shredded Gruyere over low heat until melted and smooth. Turn off heat.
- Combine Pasta and Cheese Sauce: Add the cooked pasta to the cheese sauce and stir to coat evenly.
- Prepare Breadcrumb Topping and Assemble: Toss panko breadcrumbs with olive oil. In a 9x13 baking dish, spread half of the mac and cheese. Swirl in most of the caramelized onions and most of the remaining 1 cup shredded Gruyere. Add the remaining mac and cheese on top, then sprinkle with the reserved onions, cheese, and panko mixture.
- 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. Enjoy!
Notes
- Cook pasta until just al dente as it will finish cooking in the oven to avoid mushy texture.
- Use yellow onions for their mild, sweet flavor perfect for caramelizing; avoid red onions.
- A large 12-inch deep pan is ideal for cooking onions without overcrowding to prevent steaming.
- Patience is key: allow 40-45 minutes to properly caramelize the onions for deep flavor.
- Grate your own Gruyere cheese to avoid additives in pre-shredded cheese which can affect sauce texture.
- Caramelized onions can be made up to 2 days in advance and refrigerated.
- Assemble without breadcrumbs a day ahead; let dish sit at room temperature 30 minutes before baking and add topping just before baking.
- Freeze fully cooled portions up to 2 months; thaw overnight in fridge and reheat with added milk to restore creaminess.
- Substitute cheeses like Swiss, Gouda, or white cheddar if preferred.
- Alternate pasta shapes like shells, fusilli, or rigatoni work well as substitutes.
Nutrition
- Serving Size: 1 serving (approx. 1 cup)
- Calories: 480 kcal
- Sugar: 6 g
- Sodium: 320 mg
- Fat: 24 g
- Saturated Fat: 14 g
- Unsaturated Fat: 8 g
- Trans Fat: 0 g
- Carbohydrates: 50 g
- Fiber: 3 g
- Protein: 18 g
- Cholesterol: 60 mg
