If you have ever wished that two of the coziest comfort foods could come together in one glorious dish, then this French Onion Soup Mac & Cheese Recipe is going to blow your mind. Imagine the rich, caramelized sweetness of slow-cooked onions mingling perfectly with a creamy, cheesy sauce packed with Gruyère, cheddar, and mozzarella, all hugging tender elbow macaroni. This recipe captures the soulful essence of French onion soup and transforms it into a luscious baked mac and cheese that’s irresistible, deeply comforting, and perfect for gatherings or an indulgent weeknight treat.
Ingredients You’ll Need
The magic of this French Onion Soup Mac & Cheese Recipe lies in its simple but thoughtfully chosen ingredients. Each one plays a crucial role in building layers of flavor, texture, and richness that make this dish unforgettable.
- Elbow Macaroni: The perfect shape to hold onto cheesy sauce and soft onions for every bite.
- Onions: Using large yellow onions caramelized to perfection adds the distinct sweetness and depth of French onion soup.
- Olive Oil: Helps gently cook the onions while adding a subtle fruity note.
- Butter: Adds richness and helps create the silky roux base for the cheese sauce.
- Garlic: Gives a fragrant lift that enhances the savory flavors.
- Flour: Essential for thickening the sauce to creamy perfection.
- Vegetable Broth: The backbone liquid that brings the soup element into the mac and cheese.
- Milk: Whole milk adds needed creaminess without heaviness.
- Heavy Cream: Elevates the sauce to ultra-luxurious, silky smooth texture.
- Gruyère Cheese: The star cheese for that authentic French onion soup flavor with nutty complexity.
- Sharp Cheddar Cheese: Brings a vibrant sharpness that balances the mild cheeses.
- Mozzarella Cheese: Offers meltiness and stretch that everyone loves in mac and cheese.
- Salt: Simply essential to bring out all the other flavors.
- Black Pepper: Adds mild heat and depth.
- Thyme: Fresh or dried, this herb evokes the classic French onion soup fragrance.
- Breadcrumbs: Create a crunchy, golden topping that contrasts gorgeously with creamy pasta.
- Parmesan Cheese: Mixed with breadcrumbs for an extra umami-rich crust.
How to Make French Onion Soup Mac & Cheese Recipe
Step 1: Prepare Your Oven and Dish
Start by preheating your oven to 375°F (190°C). Butter your baking dish thoroughly to prevent sticking and to add a touch of richness to the crust later on. This sets the stage for a perfectly baked finish.
Step 2: Caramelize the Onions
In a skillet, heat olive oil and one tablespoon of butter over medium heat. Add the thinly sliced yellow onions and slowly cook them while stirring often for about 25 to 30 minutes. This patient step transforms the onions into irresistibly sweet and golden caramelized pieces. Stir in minced garlic and thyme right near the end to release their wonderful aromas.
Step 3: Make the Roux and Sauce
Add the remaining butter to the same skillet, letting it melt. Sprinkle the flour evenly and stir to form a roux, cooking it gently until it’s light golden. This will thicken your sauce beautifully. Gradually whisk in the vegetable broth, followed by the milk and cream, ensuring everything is smooth and lump-free before moving ahead.
Step 4: Melt in the Cheeses and Season
Lower the heat and stir in the shredded Gruyère, sharp cheddar, and mozzarella. Watch as they melt into a rich, velvety sauce. Season with salt and black pepper to taste – this is where all the layers of flavor come alive. The combination of these cheeses perfectly channels that classic French onion soup cheese experience.
Step 5: Combine Pasta and Onion Sauce
Cook your elbow macaroni until just al dente and drain. Toss the pasta into the sauce along with the caramelized onions, ensuring every noodle is luxuriously coated. This blending step seals the harmony between soup and mac and cheese.
Step 6: Bake with Topping
Transfer the cheesy pasta mixture into your buttered baking dish. Combine the breadcrumbs and grated Parmesan, then evenly sprinkle this mixture on top to create a golden, crunchy crust. Bake in the preheated oven for 20 to 25 minutes until the top bubbles and turns beautifully golden brown.
Step 7: Rest, Garnish, and Serve
Allow your French Onion Soup Mac & Cheese Recipe to rest for about 5 minutes before serving. This resting time lets the dish firm up slightly, making it easier to serve. Sprinkle fresh thyme on top as a fragrant and colorful garnish, then dive in while it’s still warm and comforting.
How to Serve French Onion Soup Mac & Cheese Recipe
Garnishes
Fresh thyme sprigs add a lovely floral note and visual appeal. You can also lightly drizzle some truffle oil or add caramelized onion rings on top for an extra indulgent touch that elevates the whole experience.
Side Dishes
This dish pairs wonderfully with bright, crisp salads like a simple arugula with lemon vinaigrette or a refreshing cucumber salad. Roasted vegetables with contrasting flavors cut through the richness while complementing the earthy onions.
Creative Ways to Present
For a fun twist, serve the mac and cheese in individual ramekins or mini cast-iron skillets for touch-of-elegance single servings. Alternatively, create a mac and cheese bar where guests add their favorites toppings like crispy bacon, caramelized shallots, or fresh herbs.
Make Ahead and Storage
Storing Leftovers
Leftover French Onion Soup Mac & Cheese Recipe keeps well in an airtight container in the refrigerator for up to 3 days. The flavors even deepen a bit after resting, making for fantastic next-day meals.
Freezing
This dish freezes beautifully. Portion it into freezer-safe containers or wrap tightly to avoid freezer burn. It can be stored for up to 2 months. Just thaw overnight in the fridge before reheating.
Reheating
Reheat leftovers in the oven at 350°F (175°C) for about 15-20 minutes until warmed through and bubbly again. Cover with foil to keep it moist, uncover near the end to crisp up the topping. Microwaving works too if you’re short on time, but it won’t keep the crust crispy.
FAQs
Can I use a different type of pasta?
Absolutely! While elbow macaroni is traditional and holds sauce well, feel free to use shells, cavatappi, or even penne. Just adjust cooking times accordingly.
What cheese can I substitute if I don’t have Gruyère?
Swiss cheese or Emmental make excellent substitutes as they share a similar nutty, mild flavor that complements the onions perfectly.
Can I make this recipe vegetarian?
Yes, just ensure your vegetable broth is fully vegetarian and avoid any non-vegetarian stock bases. The cheese and slow caramelized onions provide plenty of rich flavors on their own.
Is it okay to use dried thyme instead of fresh?
Definitely! Use about half the amount of dried thyme as fresh, adding it during the caramelizing step to infuse the dish with its lovely herbal notes.
How long does it take to caramelize the onions properly?
Good caramelization takes patience—about 25 to 30 minutes over medium heat is ideal. Stir regularly to avoid burning and develop that deep golden color and sweet flavor.
Final Thoughts
This French Onion Soup Mac & Cheese Recipe is pure comfort food bliss that’s as impressive as it is satisfying. Its creamy, cheesy layers paired with sweet caramelized onions bring a remarkable depth you won’t forget. I truly encourage you to give this a try when you want something special to warm your heart and feed your soul. It’s perfect for cozy nights or sharing with loved ones who deserve a little extra comfort on their plates.
Print
French Onion Soup Mac & Cheese Recipe
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour
- Yield: 6 servings
- Category: Main Course
- Method: Baking
- Cuisine: French-American
- Diet: Vegetarian
Description
This French Onion Soup Mac & Cheese combines the rich, caramelized flavors of traditional French onion soup with the comforting creaminess of classic mac and cheese. Featuring a luscious blend of Gruyère, sharp cheddar, and mozzarella cheeses, topped with crispy Parmesan breadcrumbs, this baked casserole is a hearty and flavorful dish perfect for family dinners or special occasions.
Ingredients
Pasta
- 12 ounces elbow macaroni
Onion Soup Base
- 3 large yellow onions, thinly sliced
- 2 tablespoons olive oil
- 3 tablespoons butter (divided)
- 2 cloves garlic, minced
- 1 teaspoon fresh thyme leaves (or 1/2 teaspoon dried thyme)
Sauce
- 3 tablespoons all-purpose 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 and Prepare: Preheat the oven to 375°F (190°C) and butter a baking dish thoroughly to prevent sticking.
- Caramelize Onions: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the sliced onions and cook, stirring frequently, until they are deeply caramelized and golden brown, about 25 to 30 minutes. Stir in the minced garlic and thyme leaves for added flavor.
- Make the Roux and Sauce: Add the remaining 2 tablespoons of butter to the skillet. Stir in the flour to form a roux and cook for 1-2 minutes to eliminate the raw flour taste. Gradually whisk in the vegetable broth, then the milk and heavy cream, continuing to whisk until the mixture is smooth and thickened.
- Add Cheeses and Seasoning: Stir in the shredded Gruyère, sharp cheddar, and mozzarella cheeses slowly until they are fully melted and the sauce is creamy. Season the sauce with salt and black pepper to taste.
- Combine Pasta and Onion Sauce: Toss the cooked al dente elbow macaroni in the cheesy onion sauce ensuring each piece is well coated with the flavorful mixture, including the caramelized onions.
- Assemble in Baking Dish: Transfer the cheesy pasta mixture into the prepared baking dish. Mix the breadcrumbs and grated Parmesan cheese together, then evenly sprinkle this topping over the casserole.
- Bake: Bake uncovered for 20 to 25 minutes, or until the topping is golden brown and the casserole is bubbly throughout.
- Rest and Serve: Remove from oven and let the mac & cheese rest for 5 minutes to set. Garnish with fresh thyme if desired, then serve hot.
Notes
- Caramelizing onions properly is key to developing the deep French onion flavor—do not rush this step.
- You can substitute vegetarian-friendly vegetable broth for beef broth to keep the dish vegetarian.
- For a gluten-free option, use gluten-free flour and breadcrumbs.
- If you don’t have fresh thyme, dried thyme works as well; just use half the amount.
- Use freshly shredded cheese rather than pre-shredded for better melting and texture.
