French Onion Soup Mac & Cheese Recipe
This French onion soup mac & cheese recipe combines the rich, caramelized flavors of classic French onion soup with creamy, cheesy macaroni, creating a comforting and elevated twist on traditional mac & cheese. Slow-cooked onions, a savory cheese sauce with Gruyère and sharp white cheddar, and a crispy, cheesy topping give this dish a sophisticated yet nostalgic appeal.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour
- Yield: 6 servings 1x
- Category: Main Dish
- Method: Stovetop
- Cuisine: French-American
Ingredients
Scale
Onion Base
- 3 large yellow onions, thinly sliced
- 3 tbsp butter
- 2 cloves garlic, minced
- 1 tsp dried thyme
- Salt and freshly ground black pepper, to taste
Cheese Sauce
- 3 tbsp all-purpose flour
- 4 cups beef broth (or vegetable broth for vegetarian option)
- 1 cup half-and-half or heavy cream
- 1 ½ cups grated Gruyère cheese
- 1 cup sharp white cheddar cheese, grated
Pasta and Toppings
- 12 oz elbow macaroni
- Optional: French bread or baguette slices for toasting
- Extra grated cheese for topping (about ½ cup)
Instructions
- Caramelize the onions: Slowly cook thinly sliced yellow onions in butter over low heat for 30-40 minutes, stirring occasionally, until they turn golden brown and develop a rich, sweet flavor.
- Make the cheese sauce: Sprinkle flour over the caramelized onions and stir well to coat. Gradually whisk in the beef or vegetable broth and half-and-half or heavy cream until the mixture is smooth and thickened. Add minced garlic and dried thyme, then melt in Gruyère and sharp white cheddar cheeses until creamy and combined. Season with salt and pepper to taste.
- Cook the macaroni: Boil elbow macaroni according to package instructions until al dente. Drain well, reserving a small amount of pasta water in case the sauce needs to be loosened later.
- Combine pasta and sauce: Mix the cooked macaroni into the cheese sauce, ensuring every piece is evenly coated with the luscious, velvety sauce.
- Bake or broil optional topping: Transfer the mac & cheese to an oven-safe dish. Top with extra grated cheese and toasted baguette slices if desired. Broil briefly until the top is bubbly and golden brown, mimicking the classic French onion soup crouton finish. Watch carefully to avoid burning.
Notes
- For a vegetarian version, substitute beef broth with vegetable broth.
- Use half-and-half for a lighter sauce or heavy cream for extra richness.
- Keep stirring the onions frequently while caramelizing to prevent burning.
- Reserved pasta water can be used to adjust sauce consistency if it becomes too thick.
- Broil topping under close watch to prevent burning and achieve a perfect golden crust.
Keywords: French onion soup mac and cheese, caramelized onion mac and cheese, Gruyère mac and cheese, comfort food, cheesy pasta casserole
