French Onion Soup Mac & Cheese Recipe

Introduction

French Onion Soup Mac & Cheese is the comforting fusion of savory caramelized onions and creamy, cheesy pasta. This dish combines rich Gruyère and sharp cheddar with the deep flavors of classic French onion soup, baked to golden perfection. It’s a cozy twist on two beloved favorites.

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 Gruyère cheese, shredded
• 1 cup sharp cheddar cheese, shredded
• 1 cup mozzarella cheese, shredded
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1 teaspoon fresh thyme (or 1/2 teaspoon dried)
• 1 cup breadcrumbs
• 1/2 cup Parmesan cheese, grated

Instructions

1. Step 1: Preheat the oven to 375°F (190°C) and butter a baking dish.
2. Step 2: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the sliced onions and cook, stirring often, until they are deeply caramelized, about 25–30 minutes. Stir in the minced garlic and thyme during the last minute of cooking.
3. Step 3: Add the remaining 2 tablespoons of butter to the skillet. Stir in the flour to create a roux, cooking for about 1-2 minutes until lightly golden.
4. Step 4: Slowly whisk in the vegetable broth, followed by the milk and heavy cream, stirring constantly until the sauce is smooth and begins to thicken.
5. Step 5: Remove from heat and stir in the Gruyère, cheddar, and mozzarella cheeses until fully melted. Season the sauce with salt and black pepper.
6. Step 6: Cook the elbow macaroni to al dente according to package instructions, then drain and toss it with the cheese sauce and caramelized onions.
7. Step 7: Transfer the mac and cheese mixture to the prepared baking dish. In a small bowl, mix the breadcrumbs with the Parmesan cheese and sprinkle evenly on top.
8. Step 8: Bake in the preheated oven for 20–25 minutes, or until the topping is golden and the dish is bubbly.
9. Step 9: Let the mac and cheese rest for 5 minutes before serving. Garnish with additional fresh thyme if desired, and serve hot.

Tips & Variations

• For deeper flavor, use beef broth instead of vegetable broth to mimic traditional French onion soup.
• Swap mozzarella for fontina or Swiss cheese for a different texture and taste.
• Add a splash of white wine when cooking the onions for a subtle acidity.
• Use panko breadcrumbs for a crunchier topping.
• Caramelize the onions slowly to develop maximum sweetness and richness.

Storage

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven or microwave until warmed through, adding a splash of milk to loosen the sauce if needed.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I make this recipe vegetarian?

Yes, using vegetable broth ensures the dish remains vegetarian-friendly. Avoid using beef broth or any meat-based products.

What pasta works best for this mac and cheese?

Elbow macaroni is traditional and works well to hold the cheese sauce, but you can also use shell pasta or cavatappi for a similar effect.

French Onion Soup Mac & Cheese Recipe

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★★★★★

4.9 from 79 reviews

French Onion Soup Mac & Cheese is a comforting twist on the classic mac and cheese, infused with the rich, caramelized flavor of slow-cooked onions and layers of melty Gruyère, cheddar, and mozzarella cheeses. Baked to golden perfection with a crispy Parmesan breadcrumb topping, this dish perfectly combines the savory depth of French onion soup with creamy pasta indulgence.

• Author: Lena
• Prep Time: 15 minutes
• Cook Time: 55 minutes
• Total Time: 1 hour 10 minutes
• Yield: 6 servings 1x
• Category: Main Dish
• Method: Baking
• Cuisine: French-American

Ingredients

Scale 1x2x3x

Pasta

• 12 ounces elbow macaroni

Onion Base

• 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

Cheese

• 2 cups shredded Gruyère cheese
• 1 cup shredded sharp cheddar cheese
• 1 cup shredded mozzarella cheese

Seasonings and Topping

• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1 cup breadcrumbs
• 1/2 cup grated Parmesan cheese

Instructions

1. Preheat Your Equipment: Preheat your oven to 375°F (190°C) and butter a baking dish thoroughly to prevent sticking and for easy cleanup.
2. Caramelize the Onions: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the thinly sliced onions and cook gently, stirring often, until they become deeply caramelized and golden brown, about 25 to 30 minutes. This slow-cooking process develops rich, sweet flavors. Stir in minced garlic and thyme towards the end to add aromatic depth.
3. Make the Roux: Add the remaining 2 tablespoons of butter to the skillet with the onions, allowing it to melt. Stir in the flour and cook for a minute to form a roux, which will thicken the sauce.
4. Prepare the Cheese Sauce: Gradually whisk in the vegetable broth, followed by the whole milk and heavy cream, stirring continuously until the mixture is smooth and starts to thicken.
5. Add Cheese and Season: Stir in Gruyère, sharp cheddar, and mozzarella cheeses until fully melted and creamy. Season the sauce with salt and black pepper to taste.
6. Combine Pasta and Sauce: Cook the elbow macaroni until al dente according to package directions, drain, then toss with the cheese sauce and caramelized onions, ensuring the pasta is evenly coated.
7. Assemble the Dish: Transfer the mac and cheese mixture into the prepared buttered baking dish.
8. Add Topping: Mix the breadcrumbs with grated Parmesan cheese and sprinkle evenly over the top of the dish to create a crunchy golden crust during baking.
9. Bake: Place the baking dish in the preheated oven and bake for 20 to 25 minutes until the topping is bubbly and golden brown.
10. Serve: Remove from the oven and let the dish rest for 5 minutes. Garnish with fresh thyme if desired and serve hot for the best flavor experience.

Notes

• Caramelizing onions slowly over medium heat is key to developing the deep sweet flavor typical of French onion soup.
• Using a blend of Gruyère, cheddar, and mozzarella balances sharpness, creaminess, and meltiness in the cheese sauce.
• Ensure pasta is al dente before baking to prevent it from becoming mushy in the casserole.
• The breadcrumb and Parmesan topping adds a delicious crunchy texture contrast to the creamy pasta.
• If you prefer a richer sauce, you can add a touch more heavy cream before baking.
• Vegetable broth can be substituted with beef broth for a more traditional French onion soup flavor, but it will affect the dietary classification.

Keywords: French onion soup, mac and cheese, baked pasta, caramelized onions, Gruyère, comfort food, cheesy casserole