Smoked Salmon Croque Monsieur With Osetra Caviar Recipe

Warm the milk

Place the 2 cups of whole milk in a small saucepan and warm over low heat until just steaming — do not boil. Keep warm while you make the roux.

Make roux

In a medium saucepan over medium heat, melt 3 tablespoons unsalted butter. Add 3 tablespoons all-purpose flour and whisk continuously for 1–2 minutes until the raw flour scent cooks off and mixture is lightly golden (do not brown).

Finish béchamel

Gradually whisk the warm milk into the roux in three additions, whisking until smooth and thickened between additions (about 5 minutes total). Reduce heat to low, stir in 1/2 tsp Dijon mustard, 1/8 tsp grated nutmeg, 1/2 tsp kosher salt and optional 1/8 tsp white pepper. Cook 1–2 more minutes until the sauce coats the back of a spoon. Remove from heat and set aside.

Taste and adjust seasoning; the béchamel should be slightly seasoned because the smoked salmon and caviar will be salty.

Prep bread

Preheat your oven to 400°F (200°C). Lightly butter one side of each of the 8 bread slices with the 4 tablespoons softened butter. On the unbuttered sides of 4 slices, spread a thin layer of 1 tablespoon Dijon mustard each (reserve remaining mustard).

Assemble base

Place the 4 mustard-spread slices buttered-side down on a work surface. Spoon a thin layer (about 2–3 tablespoons) of the warm béchamel onto each slice and spread evenly to cover most of the surface. Sprinkle a light layer (about 2–3 tablespoons) of the grated Gruyère/Emmental mix on top of the béchamel.

Add smoked salmon

Arrange about 50 g of smoked salmon per sandwich (200 g total divided among 4) on top of the cheese layer, folding the salmon so it lies evenly and has some volume. Zest the lemon over the salmon lightly and squeeze a few drops of lemon juice over each portion to brighten flavor. Grind about 1/8 to 1/4 tsp freshly ground black pepper across the salmon.

Top and bake

Place the remaining 4 bread slices on top, buttered-side up, to close the sandwiches. Place assembled sandwiches on a baking sheet. Spread a thin coat (about 1–2 tablespoons each) of béchamel over the top of each sandwich, then sprinkle the remaining grated Gruyère and Emmental mixture generously over the béchamel to form a gratin crust.

Gratinate

Bake in the preheated oven until the cheese is melted and bubbling and the tops are golden brown, about 8–12 minutes. For a deeper golden crust, switch the oven to broil (grill) for 1–2 minutes—watch closely to prevent burning.

Remove sandwiches from the oven and let rest 1–2 minutes so the béchamel settles.

Plate and dress

Using a sharp knife, cut each sandwich in half on the diagonal. Place two halves per plate. Spoon approximately 15 g of Osetra caviar onto the top center of each sandwich half (about 30 g caviar per full sandwich). Be gentle to preserve the pearls; serve chilled but not icy.

Garnish

Sprinkle each plated sandwich with 1/2 tablespoon finely snipped chives and a few microgreens if using. Serve with a lemon wedge on the side for additional brightness.

Serve immediately so the caviar is enjoyed fresh atop the warm croque. Recommend pairing with chilled Champagne or dry sparkling wine.