If you’ve ever dreamed of combining the soul-soothing comfort of French onion soup with the cheesy, creamy goodness of mac and cheese, then you’re in for a real treat with this French Onion Soup Mac & Cheese Recipe. It brings the rich, slow-caramelized onions, earthy thyme, and layers of melty Gruyère, sharp cheddar, and mozzarella together with perfectly cooked elbow macaroni. This dish takes cozy to a whole new level, making it a standout crowd-pleaser for dinner, special occasions, or any time you want to savor something truly heartwarming.
Ingredients You’ll Need
Simple ingredients form the foundation of this dish, each selected to build layers of flavor and a luscious texture. From the sweet caramelized onions to the medley of cheeses, every component contributes something special that transforms this mac and cheese into a gourmet delight.
- Elbow Macaroni: The classic pasta shape that holds sauce beautifully for a perfect bite every time.
- Onions: Thinly sliced yellow onions caramelized for that deep, sweet flavor that’s essential to the French onion soup essence.
- Olive Oil: Adds a subtle fruitiness and helps soften the onions without overpowering their natural sweetness.
- Butter: Provides richness and is crucial for making the roux that thickens the sauce.
- Garlic: Just a hint brings an aromatic complexity to the dish.
- Flour: Combines with butter to create the roux, the thickening agent for the creamy sauce.
- Vegetable Broth: Emulates the classic broth in French onion soup, adding depth without heaviness.
- Milk: Gives creaminess and balances the sharpness of the cheeses.
- Heavy Cream: Amplifies richness, ensuring a silky sauce.
- Gruyère Cheese: The star cheese in French onion soup, it melts superbly and adds nutty, savory flavor.
- Sharp Cheddar Cheese: Adds a bold tang and sharpness that contrasts beautifully with milder cheeses.
- Mozzarella Cheese: Provides stretch and gooey texture for ultimate comfort.
- Salt: Enhances all the flavors naturally.
- Black Pepper: Adds a subtle heat and complexity.
- Thyme: Fresh or dried, it gives that unmistakable herby note found in French onion soup.
- Breadcrumbs: For a golden, crispy topping that adds a wonderful crunch.
- Parmesan Cheese: Mixed with breadcrumbs, it contributes an intense umami punch to the crust.
How to Make French Onion Soup Mac & Cheese Recipe
Step 1: Prepare Your Oven and Baking Dish
Start by preheating your oven to 375 degrees Fahrenheit (190 degrees Celsius). Butter your baking dish thoroughly to ensure the finished mac and cheese won’t stick and will have a beautiful edge crisp up during baking.
Step 2: Caramelize the Onions
Heat olive oil and one tablespoon of butter in a skillet over medium heat. Add in your thinly sliced onions and patiently cook them, stirring often, for about 25 to 30 minutes until they turn a rich golden brown. This slow caramelization develops the signature sweet, deep flavor reminiscent of French onion soup. Just before moving on, stir in the minced garlic and thyme, letting their aroma blend in with the onions.
Step 3: Create the Roux and Sauce Base
Add the remaining butter to your skillet. Sprinkle in the flour and stir continuously to form a smooth roux. This step is key to creating a creamy, thickened sauce. Gradually whisk in the vegetable broth, then the milk and heavy cream, making sure the mixture stays smooth and bubble-free as it begins to thicken.
Step 4: Melt in the Cheeses and Season
Once the sauce has thickened, stir in the shredded Gruyère, sharp cheddar, and mozzarella cheese until they melt completely into a velvety, luscious cheese sauce. Season the sauce with salt and black pepper to taste, balancing the flavors perfectly. Toss your cooked elbow macaroni into this cheesy onion sauce, ensuring every piece is coated with that irresistible richness.
Step 5: Assemble and Top Your Mac & Cheese
Pour the cheesy pasta mixture into the buttered baking dish. To add that unforgettable crispy, golden crust, mix together the breadcrumbs with grated Parmesan cheese and sprinkle this mixture evenly over the top.
Step 6: Bake to Perfection
Bake the dish in your preheated oven for 20 to 25 minutes. Look for the sauce to be bubbly and the topping to have turned a gorgeous golden brown, signaling that perfect balance of gooey and crunchy is achieved.
Step 7: Rest and Garnish
Allow the mac and cheese to rest for about five minutes after baking. This little pause lets the sauce set slightly, making it easier to serve. Garnish with a few sprigs of fresh thyme to add a delightful herbal note and an inviting presentation.
How to Serve French Onion Soup Mac & Cheese Recipe
Garnishes
Fresh thyme or even a sprinkle of finely chopped chives elevate the dish visually and complement the onion and cheese flavors wonderfully. A pinch of crushed black pepper on top adds a subtle kick and finishes it off beautifully.
Side Dishes
This rich, flavorful mac and cheese pairs splendidly with crisp, refreshing sides like a simple green salad dressed with a light lemon vinaigrette or roasted seasonal vegetables to balance the indulgence.
Creative Ways to Present
For a fun twist, serve individual portions in small ramekins topped with extra breadcrumbs and broil until bubbly and golden. You can also add caramelized onions or a drizzle of balsamic reduction for an extra layer of flavor and impressive plating.
Make Ahead and Storage
Storing Leftovers
Leftover French Onion Soup Mac & Cheese Recipe keeps wonderfully in the refrigerator for up to three days when stored in an airtight container. The flavors actually deepen, making it perfect for next-day indulgence.
Freezing
You can freeze this mac and cheese before baking. Just assemble it in a freezer-safe dish, wrap tightly, and freeze for up to two months. When ready to eat, thaw overnight in the refrigerator before baking as directed.
Reheating
The best way to reheat is in the oven at 350 degrees Fahrenheit, covered with foil to prevent drying out, for about 20 minutes or until heated through. For a quicker option, gently warm in the microwave, stirring occasionally to keep it creamy.
FAQs
Can I use other pasta shapes for this recipe?
Absolutely! While elbow macaroni is classic and holds the sauce wonderfully, small shells, cavatappi, or penne will work just as well and add a fun twist.
Is it possible to make this dish vegetarian-friendly?
Yes, simply use vegetable broth instead of beef broth and double-check that your cheese is vegetarian-friendly. This recipe already calls for vegetable broth, so it’s a delicious vegetarian option as is.
Can I prepare the caramelized onions ahead of time?
Definitely! Caramelized onions can be made a day or two ahead and refrigerated. Just warm them slightly before adding to the sauce for convenience.
How do I make this recipe gluten-free?
Substitute the all-purpose flour with a gluten-free flour blend to make the roux and use gluten-free breadcrumbs on top. The rest of the ingredients are naturally gluten-free.
What if I don’t have Gruyère cheese?
You can substitute Gruyère with Swiss cheese or even Emmental. These cheeses melt well and have similar nutty flavors that complement the French onion character.
Final Thoughts
This French Onion Soup Mac & Cheese Recipe is a luscious symphony of flavors that feels both homey and special. It’s perfect for cozy nights, impressing guests, or just turning an ordinary dinner into a memorable meal. Once you try it, it might just become one of your all-time favorite comfort foods. So go ahead, gather your ingredients, and indulge in this cheesy, caramelized onion goodness that warms the soul with every bite.
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French Onion Soup Mac & Cheese Recipe
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Total Time: 1 hour
- Yield: 6 servings
- Category: Main Dish
- Method: Baking
- Cuisine: French-American
- Diet: Vegetarian
Description
This French Onion Soup Mac & Cheese combines the rich, caramelized flavors of classic French onion soup with the creamy indulgence of mac and cheese. Featuring a luxurious cheese sauce made with Gruyère, sharp cheddar, and mozzarella, layered with tender elbow macaroni and topped with crispy Parmesan breadcrumbs, this comforting casserole is baked to golden perfection. Perfect for a cozy dinner that elevates comfort food to a gourmet experience.
Ingredients
Pasta
- 12 ounces elbow macaroni
Onions and Aromatics
- 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)
Cheese 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
- Prepare the Oven and Baking Dish: Preheat the oven to 375°F (190°C) and butter a baking dish evenly to prevent sticking and help with browning.
- Caramelize the Onions: Heat olive oil and 1 tablespoon of butter in a skillet over medium heat. Add the thinly sliced onions and cook, stirring often, until they become deeply caramelized, soft, and golden brown, which should take about 25–30 minutes. Stir in minced garlic and thyme during the last few minutes of cooking to release their aromas.
- Create the Roux and Sauce Base: Add the remaining 2 tablespoons of butter to the skillet. Once melted, whisk in the flour to create a roux, cooking it for about 1-2 minutes to remove the raw flour taste. Slowly pour in the vegetable broth while whisking continuously to avoid lumps, then add the milk and heavy cream gradually, stirring until the sauce is smooth and starts to thicken.
- Add Cheese and Season: Stir in the shredded Gruyère, sharp cheddar, and mozzarella cheeses until fully melted and combined into a rich, creamy cheese sauce. Season the mixture with salt and black pepper to taste.
- Combine Pasta and Sauce: Cook the elbow macaroni until al dente according to package instructions, then drain. Toss the cooked pasta into the cheese sauce along with the caramelized onions, mixing thoroughly to coat the pasta evenly.
- Assemble and Top: Transfer the cheesy pasta and onion mixture into the prepared baking dish. Mix the breadcrumbs with grated Parmesan cheese and sprinkle this topping evenly over the assembled casserole for a crispy, golden crust.
- Bake: Bake the dish in the preheated oven for 20–25 minutes until the top is bubbly and beautifully golden brown.
- Rest and Serve: Allow the baked mac and cheese to rest for 5 minutes to set. Garnish with additional fresh thyme leaves if desired, then serve hot and enjoy the comforting flavors.
Notes
- For extra flavor, try adding a splash of dry white wine to the onion caramelizing step.
- Swap vegetable broth for beef broth for a richer, more traditional French onion soup flavor, if not vegetarian.
- Use gluten-free flour and breadcrumbs to make this recipe gluten-free.
- To make ahead, assemble but do not bake. Cover and refrigerate for up to 24 hours, then bake before serving.
- Leftovers can be refrigerated for up to 3 days and reheated in the oven for the best texture.
