Introduction

French Onion Soup Mac & Cheese is a comforting twist on two classic favorites, blending rich caramelized onions and a blend of melted cheeses with tender pasta. This recipe offers deep, savory flavors topped with a crispy breadcrumb crust, perfect for cozy dinners.

A close-up view of a baked macaroni and cheese dish in a white bowl, showing creamy macaroni pasta covered with a golden brown, slightly crispy top layer of melted cheese. The cheese has browned spots and is bubbly, with some green herb flakes sprinkled on top. A fork lifts a cheesy portion, with gooey melted cheese stretching from the bowl, highlighting the rich, soft texture of the macaroni below the crispy top. The bowl sits on a white marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

12 ounces elbow macaroni
3 large yellow onions, thinly sliced
2 tablespoons olive oil
3 tablespoons butter
2 cloves garlic, minced
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
1 teaspoon fresh thyme (or 1/2 teaspoon dried)
1 cup breadcrumbs
1/2 cup grated Parmesan cheese

Instructions

Step 1: Preheat the oven to 375°F (190°C) and butter a baking dish to prepare for baking.
Step 2: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add sliced onions and cook, stirring often, until caramelized, about 25–30 minutes. Stir in minced garlic and thyme.
Step 3: Add the remaining 2 tablespoons of butter to the skillet. Stir in flour to create a roux. Slowly whisk in vegetable broth, then milk and heavy cream until the mixture is smooth and combined.
Step 4: Stir in Gruyère, cheddar, and mozzarella cheeses until melted. Season the sauce with salt and black pepper to taste.
Step 5: Cook elbow macaroni until just al dente according to package instructions. Drain and toss the pasta with the cheese sauce and caramelized onions.
Step 6: Transfer the mac and cheese mixture to the prepared baking dish. In a small bowl, combine breadcrumbs with grated Parmesan cheese and sprinkle evenly over the top.
Step 7: Bake uncovered for 20–25 minutes until the dish is bubbly and the topping is golden and crispy.
Step 8: Let the baked mac and cheese rest for 5 minutes before serving. Garnish with additional thyme if desired and serve hot.

Tips & Variations

Caramelize the onions slowly over medium heat to develop a deep, rich flavor.
Cook pasta just until al dente to prevent it from becoming mushy after baking.
Use a mix of cheeses like Gruyère, sharp cheddar, and mozzarella for a complex, creamy texture and taste.
Bake uncovered to keep the breadcrumb topping crisp and golden.
For a richer sauce, substitute some milk with more heavy cream if desired.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven at 350°F (175°C) until warmed through, to maintain the crispy topping. Microwave reheating is possible but may soften the crust.

How to Serve

The image shows a close-up of a golden-brown baked mac and cheese in a white bowl with a dark rim. The top layer is a crispy, browned cheese crust with small green herb pieces sprinkled over it. Underneath the crust is a creamy, gooey layer of melted cheese that stretches as a spoon lifts a portion of tender elbow macaroni coated in the rich sauce. The white marbled surface beneath the bowl provides a clean, bright contrast, emphasizing the warm colors and textures of the dish. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use a different type of pasta?

Yes, short pasta shapes like penne, cavatappi, or shells work well as they hold the sauce nicely, but elbow macaroni is traditional for mac and cheese.

Can I make this recipe ahead of time?

You can assemble the dish ahead and refrigerate it unbaked for up to 24 hours. When ready to eat, bake it using the same instructions, adding a few extra minutes if baking from cold.