Croûte au Fromage

Jump to Recipe

Croûte au Fromage is proof that simple ingredients can create extraordinary flavor. This French classic layers caramelized onions, prosciutto, and cheese on crusty bread for the ultimate cozy bite.

Overhead shot of croûte au fromage in a cast iron skillet.

What is Croûte au Fromage?

Croûte au Fromage translates to “cheese on toast” in French, and it’s exactly what it sounds like! It’s bread topped with rich, melty cheese. This dish has deep roots in the Alpine regions of France and Switzerland, where hearty, warming meals are a way of life during cold winters.

Historically, it’s believed that Croûte au Fromage came about as a clever way to use up stale bread, local cheese, and wine—three staples you’d find in a mountain village kitchen. Rather than waste old bread, it would be toasted or soaked with a splash of wine, then topped with cheese and baked until bubbling and golden. Some versions keep it simple, while others add layers of flavor with cured meats, herbs, onions, or even mushrooms.

In essence, it’s the sophisticated cousin of grilled cheese. Whether you serve it as an appetizer, a light lunch, or a late-night indulgence, croute au fromage will always be a hit!

Croûte au fromage (cheesy toast) in a cast iron skillet with thyme on top.

Why We Love This Croûte au Fromage Recipe

Cozy & comforting. Between the golden bread, sweet caramelized onions, and melty cheese, every bite feels like a hug.
A touch of luxury. The addition of white wine and prosciutto adds a luxurious touch without making it complicated.
Easy to adapt. Swap cheeses, try different breads, or add extras like mushrooms or fresh herbs to make it your own.
Make-ahead friendly. The onions can be caramelized ahead of time, so all you need to do is assemble and bake.
Perfect for any occasion. Serve with a crisp salad for lunch, or make smaller slices for an elegant appetizer spread.

Ingredients You Need

Raclette Cheese: Raclette has a nutty, slightly pungent flavor that melts beautifully. If you can’t find raclette, Gruyère, Swiss, or fontina are great options.
Onions: Slow-cooked until sweet and jammy, caramelized onions balance the salty cheese.
Butter: Used to caramelize the onions.
Bread: Stale bread is ideal because it soaks up the wine without getting soggy. Rustic country bread or a crusty baguette works beautifully, but definitely choose something sturdy.
Garlic: Rubbing the bread with garlic gives a subtle flavor.
Prosciutto: Adds salty, savory richness and a touch of elegance. You could also use speck, pancetta, or skip the meat for a vegetarian version.
White Wine: Brightens the flavor and soaks into the bread for a subtle tang. Choose a dry wine you’d enjoy drinking.
Freshly Ground Black Pepper: Balances the richness and adds a gentle heat.
Freshly Ground Nutmeg: A small pinch of nutmeg enhances the cheese’s flavor without making the dish sweet. It’s a classic Alpine touch!
Fresh Thyme: Adds a fresh, herbal note to cut through the richness.

Variations & Substitutions

Vegetarian: Omit the prosciutto and try adding sautéed mushrooms or roasted red peppers for extra flavor.
Cheese: If you don’t have raclette, fontina cheese works well. Any melty white cheese would work though!
Extra toppings: Add a fried or poached egg, a handful of arugula, or a drizzle of honey for a touch of sweetness.
Wine-free version: Replace the wine with vegetable or chicken broth for a non-alcoholic option that still adds depth.

Croûte au fromage in a cast iron skillet garnished with thyme.

How to Make French Cheese on Toast

Caramelize the Onions: In a skillet, melt 2 tablespoons of butter over medium heat. Add the sliced onions and cook slowly, stirring occasionally, until caramelized and golden brown, about 20-25 minutes.
Preheat & Prep: Preheat your oven to 400F. Rub the garlic clove over both slices of bread.
Assemble: Place the bread slices on a baking dish. Sprinkle the bread with white wine. Arrange prosciutto on each toast. Layer the caramelized onions evenly on top of each slice. Arrange the slices of Raclette cheese over the onions.
Bake: Bake in the preheated oven for about 10-12 minutes, or until the cheese is melted and bubbly.
Serve & Enjoy: Season with freshly ground black pepper and a sprinkle of freshly ground nutmeg and fresh thyme. Serve hot!

Caramelizing onions in a skillet with a wooden spoon.

Drizzling white wine on top of bread in a skillet.

Tips for Success

Use stale, sturdy bread. It holds up better to the wine without becoming soggy. If your bread is fresh, toast it lightly first.
Mind the cheese! Raclette melts quickly, so keep an eye on it so it doesn’t overcook and separate. You want it melty and bubbly, but not so melted that it will harden quickly.
Don’t rush the onions. Unfortunately it does take some time to properly caramelize the onions. I don’t recommend skipping this step, since it adds so much flavor to the dish in the end!
Serve immediately! Croûte au Fromage is best enjoyed piping hot, right out of the oven.

Serving Suggestions

With Soup: Pair with French onion soup, tomato soup, or creamy potato leek soup for a comforting meal.
With Salad: Try it with a fresh salad on the side like a rapini orange salad with tahini dressing or a warm lentil kale salad!
As an Appetizer: Cut into smaller pieces and serve on a platter with cornichons, grapes, olives, and charcuterie.
Brunch-Style: Top with a fried egg and serve alongside roasted potatoes!

Spatula lifting a piece of cheesy toast from a skillet.

Frequently Asked Questions

Can I make Croûte au Fromage ahead of time?

You can caramelize the onions up to 3 days in advance and store them in the fridge. Assemble and bake just before serving for the best texture.

What’s the best bread for Croûte au Fromage?

A rustic country loaf, baguette, or sourdough works well. The bread should be sturdy enough to hold the toppings without collapsing.

How do I store leftovers?

While Croûte au fromage is best fresh, you can store leftovers in an airtight container in the fridge for up to 2 days. Reheat in the oven until warm and bubbly.