Brunch Recipe: Mushroom Croque Monsieur with Truffle Butter Bechamel

Sautéed exotic mushrooms are smothered in truffle butter béchamel and two types of melty cheese in this twist on the classic bistro sandwich. Perfect for lunch or a light supper, serve with cornichons and dressed baby greens. Or top with a fried egg for an upgraded Croque Madame.

Check our post about Croque Monsieur for a little more on this beloved sandwich.


  • 6 tablespoons Black Truffle Butter, divided use
  • 1 pack Organic Chef’s Mix Mushrooms, trimmed and chopped
  • 1 teaspoon fresh thyme leaves
  • 1 tablespoon fresh chives, divided use
  • Kosher salt & freshly ground black pepper
  • ¼ cup all-purpose flour
  • 1½ cups whole milk
  • 1 tablespoon Dijon mustard
  • Freshly grated nutmeg, to taste
  • 8 slices Pain de Campagne
  • 3 ounces Gruyere cheese, grated
  • 3 ounces young Fontina cheese, grated
  • Cornichons, for serving


  1. In a large skillet over medium-high heat, melt 2 tablespoons of black truffle butter. Add mushrooms and thyme, turn to coat; season with salt and pepper. Sauté until mushrooms have released their liquid and are deeply golden brown and slightly dry. Stir in half of the chives. Set aside.
  2. In a saucepan over medium-high heat, melt remaining 4 tablespoons of truffle butter. Add flour and whisk frequently until mixture turns golden brown and foamy, about 4 minutes. Gradually add milk, whisking constantly until smooth and thickened, about 4 more minutes. Remove from heat and whisk in mustard; season with nutmeg, salt, and pepper, to taste.
  3. Lay all eight slices of country bread on a sheet pan. Spread each slice with a thick coating of béchamel in an even layer. On four of the slices, top béchamel with the reserved mushroom mixture and half of the cheese. Lay the béchamel-only slices on top and spread the rest of the cheese over the béchamel. Sprinkle with the remaining chives.
  4. Bake until the cheese is melted and the tops of the sandwiches are golden brown and crusty, about 15-20 minutes. Serve immediately, with cornichons and baby greens dressed with vinaigrette.

One Comment Add yours

  1. mistimaan says:

    Loved your yummy recipe 🙂

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.