Description

This French Onion Soup Mac & Cheese combines the classic caramelized onion flavor and rich cheese sauce into a comforting baked pasta dish. The sweetness of slowly caramelized onions blends perfectly with Gruyère, sharp cheddar, and mozzarella cheeses, topped with a golden breadcrumb and Parmesan crust. Perfect for a cozy dinner, this dish delivers all the warmth and flavor of French onion soup in a creamy, cheesy macaroni bake.

Ingredients

Scale

Pasta

12 ounces elbow macaroni

Onions & Aromatics

3 large yellow onions, thinly sliced
2 tablespoons olive oil
3 tablespoons butter, divided
2 cloves garlic, minced
1 teaspoon fresh thyme (or 1/2 teaspoon dried thyme)

Sauce

3 tablespoons flour
2 cups vegetable broth
2 cups whole milk
1/2 cup heavy cream
2 cups shredded Gruyère cheese
1 cup shredded sharp cheddar cheese
1 cup shredded mozzarella cheese
1 teaspoon salt
1/2 teaspoon black pepper

Topping

1 cup breadcrumbs
1/2 cup grated Parmesan cheese

Instructions

Preheat Your Equipment: Preheat the oven to 375°F (190°C) and butter a suitable baking dish to prepare it for the macaroni and cheese.
Caramelize Onions: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the thinly sliced onions and cook slowly, stirring often, until the onions are deeply caramelized and golden brown, about 25–30 minutes. Stir in the minced garlic and fresh or dried thyme to infuse flavor.
Make the Roux and Sauce: Add the remaining 2 tablespoons of butter to the skillet with the onions. Stir in the flour to create a roux and cook for a minute or two. Slowly whisk in the vegetable broth, followed by the milk and heavy cream, stirring continuously until the sauce is smooth and thickened.
Add Cheese and Season: Stir in the shredded Gruyère, sharp cheddar, and mozzarella cheeses into the sauce until fully melted. Season the cheese sauce with salt and black pepper to taste.
Combine with Pasta: Cook the elbow macaroni until al dente according to package instructions, then drain. Toss the pasta with the cheese sauce and caramelized onions until evenly coated.
Assemble and Top: Transfer the cheesy pasta mixture into the prepared baking dish. In a small bowl, mix the breadcrumbs with the grated Parmesan cheese and sprinkle evenly over the top.
Bake: Bake in the preheated oven for 20–25 minutes until the top is golden, bubbly, and crisp.
Serve: Remove from oven and let the dish rest for 5 minutes. Garnish with additional thyme if desired and serve hot for a comforting meal.

Notes

Caramelizing onions slowly is key to developing the sweet, deep flavor essential to this dish.
Use freshly grated cheeses for the best melting and flavor.
For a richer sauce, use whole milk and heavy cream as specified.
If preferred, substitute vegetable broth with beef broth for a more traditional French onion flavor.
Let the dish rest before serving to allow the sauce to set slightly, making serving easier.
Breadcrumbs can be seasoned with herbs or a little garlic powder for extra flavor.

Prep Time: 15 minutes
Cook Time: 55 minutes
Category: Dinner
Method: Baking
Cuisine: French-inspired American

Keywords: French onion soup, macaroni and cheese, caramelized onions, baked pasta, comfort food, cheesy bake