French Onion Soup Mac & Cheese Recipe
A rich and comforting twist on classic mac & cheese inspired by French onion soup, featuring caramelized onions, a creamy cheese sauce with Gruyère, cheddar, and mozzarella, topped with a crunchy Parmesan breadcrumb crust and baked to golden perfection.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour
- Yield: 6 servings 1x
- Category: Main Course
- Method: Baking
- Cuisine: American
- Diet: Vegetarian
Ingredients
Scale
Pasta
- 12 ounces elbow macaroni
Onion Mixture
- 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 Oven and Prepare Dish: Preheat your oven to 375°F (190°C) and butter a baking dish to prevent sticking.
- Caramelize Onions: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the thinly sliced onions and cook for 25–30 minutes, stirring often, until the onions are deeply caramelized and golden brown. Stir in minced garlic and thyme towards the end to infuse flavor.
- Make the Roux and Sauce: Add the remaining butter to the skillet with the onions. Stir in flour to create a roux, cooking briefly to remove the raw flour taste. Slowly whisk in the vegetable broth, followed by the whole milk and heavy cream, ensuring the sauce becomes smooth and thickened.
- Add Cheese and Season: Stir in the shredded Gruyère, sharp cheddar, and mozzarella cheeses until fully melted and blended into the sauce. Season the cheese sauce with salt and black pepper to taste.
- Combine Pasta and Sauce: Cook elbow macaroni until al dente according to package instructions. Drain and toss the pasta into the cheese sauce along with the caramelized onions, mixing well to evenly coat everything.
- Prepare Topping and Assemble: In a small bowl, combine breadcrumbs with grated Parmesan cheese. Transfer the mac & cheese mixture into the prepared baking dish and evenly sprinkle the breadcrumb-Parmesan mixture on top.
- Bake: Bake in the preheated oven for 20–25 minutes, or until the top is bubbly, golden brown, and crispy.
- Rest and Serve: Remove from the oven and let rest for 5 minutes. Garnish with fresh thyme if desired, then serve hot and enjoy your French Onion Soup Mac & Cheese.
Notes
- Caramelizing onions slowly is key to developing deep flavor; patience is important during this step.
- Using a blend of Gruyère, sharp cheddar, and mozzarella creates a balanced cheese sauce with creaminess and tang.
- For a vegetarian version, ensure the vegetable broth is used instead of beef broth.
- Breadcrumb topping adds delightful crunch; you can substitute panko breadcrumbs for extra crispiness.
- Leftovers can be refrigerated for up to 3 days and reheated in the oven for best results.
Keywords: French onion soup, mac and cheese, caramelized onions, Gruyère cheese, baked mac and cheese, comfort food, creamy cheese sauce
