Bistro-Style Croque Monsieur

Inspired by versions served at Parisian bistros, chef Alexia Duchêne’s (of Le Chêne in New York City) take on France’s most decadent sandwich swaps the usual béchamel for a Comté cheese– and thyme-infused mornay sauce. Ooey-gooey raclette cheese adds a second layer of richness inside the sandwich, along with French ham and zingy Dijon mustard, between slices of super soft pain de mie (a Pullman loaf or Japanese milk bread also work well).

The lot gets toasted under the broiler, allowing the sauce to char and melt into a velvety smooth shawl over this restaurant-worthy croque monsieur. Duchêne serves the sandwich with a simple salad of dressed greens, providing a bright and zippy foil.

Note: You might find yourself with a spot of leftover sauce. If so, gently heat until fluid and serve on the side. Or, as a cook’s treat, dip crust pieces of bread into it for an impromptu fondue situation.

Recipe information

• Total Time

  45 minutes (plus cooling)

• Yield

  Makes 2

Total Time

45 minutes (plus cooling)

Yield

Makes 2

Ingredients

1

3

6

5

5

4

2

4

10

1

Need to make a substitution?

Preparation

1. Step 1

   Bring 1 cup plus 2 Tbsp. whole milk and 3 sprigs thyme to a simmer in a small saucepan over medium heat. Immediately reduce heat to low and keep warm.

   Step 2

   Melt 2 Tbsp. unsalted butter in another small saucepan over medium heat. Add 5 Tbsp. (39 g) all-purpose flour and cook, whisking constantly, until no pockets of dry flour remain, about 1 minute. Remove thyme from warm milk; discard. Gradually pour milk into roux, whisking constantly until combined. Bring to a simmer, then immediately remove pan from heat. Let béchamel sit until no longer hot but still warm.

   Step 3

   Add 5 oz. Comté cheese, coarsely grated, to béchamel and stir until melted and combined. Add freshly grated nutmeg to taste and season with kosher salt. Let mornay sauce cool, then cover with plastic wrap, pressing directly against the surface, and chill until ready to use.

   Step 4

   Spread one side of two 1"-thick slices pain de mie or other white sandwich bread with 2 Tbsp. Dijon mustard, dividing evenly. Top with 2 oz. raclette cheese, thinly sliced into irregular ribbons with a vegetable peeler, dividing evenly, then divide 10 thin slices French or other ham, between bread slices. Top with another 2 oz. raclette cheese, thinly sliced into irregular ribbons with a vegetable peeler, then close up sandwiches with two 1"-thick slices pain de mie or other white sandwich bread.

   Step 5

   Heat 1 Tbsp. vegetable or other neutral oil in a large skillet over medium. Place a sandwich in pan and top with a grill press or other heavy object (such as a another skillet) to weigh down. Add 1 Tbsp. unsalted butter and swirl so butter evenly coats bottom of pan and absorbs into sandwich. Cook sandwich until golden brown underneath, about 4 minutes. Remove press and turn sandwich; return press to sandwich. Add 1 Tbsp. unsalted butter  and swirl so butter evenly coats bottom of pan and absorbs into sandwich. Cook until second side is golden brown underneath, about 4 minutes. Continue cooking, removing weight and turning sandwich as needed to ensure neither side gets too brown, until cheese is melted, 2–3 minutes more. Transfer sandwich to a rimmed baking sheet and repeat process with remaining sandwich and remaining 2 Tbsp. unsalted butter.

   Step 6

   Heat broiler to high (if broiler is in your oven, place a rack 1 slot down from the top). Spread mornay sauce over sandwiches to make about a ¼"-thick layer. (You might not use all of the sauce.) Broil until sauce is deeply browned in spots, about 3 minutes. (Watch carefully as sandwiches can go from browned to burned very quickly.)

   Step 7

   Transfer sandwiches to plates and mound some dressed greens on the side if desired.

   Do Ahead: Sauce can be made 1 day ahead. Keep chilled.

Step 1

Bring 1 cup plus 2 Tbsp. whole milk and 3 sprigs thyme to a simmer in a small saucepan over medium heat. Immediately reduce heat to low and keep warm.

Step 2

Melt 2 Tbsp. unsalted butter in another small saucepan over medium heat. Add 5 Tbsp. (39 g) all-purpose flour and cook, whisking constantly, until no pockets of dry flour remain, about 1 minute. Remove thyme from warm milk; discard. Gradually pour milk into roux, whisking constantly until combined. Bring to a simmer, then immediately remove pan from heat. Let béchamel sit until no longer hot but still warm.

Step 3

Add 5 oz. Comté cheese, coarsely grated, to béchamel and stir until melted and combined. Add freshly grated nutmeg to taste and season with kosher salt. Let mornay sauce cool, then cover with plastic wrap, pressing directly against the surface, and chill until ready to use.

Step 4

Spread one side of two 1"-thick slices pain de mie or other white sandwich bread with 2 Tbsp. Dijon mustard, dividing evenly. Top with 2 oz. raclette cheese, thinly sliced into irregular ribbons with a vegetable peeler, dividing evenly, then divide 10 thin slices French or other ham, between bread slices. Top with another 2 oz. raclette cheese, thinly sliced into irregular ribbons with a vegetable peeler, then close up sandwiches with two 1"-thick slices pain de mie or other white sandwich bread.

Step 5

Heat 1 Tbsp. vegetable or other neutral oil in a large skillet over medium. Place a sandwich in pan and top with a grill press or other heavy object (such as a another skillet) to weigh down. Add 1 Tbsp. unsalted butter and swirl so butter evenly coats bottom of pan and absorbs into sandwich. Cook sandwich until golden brown underneath, about 4 minutes. Remove press and turn sandwich; return press to sandwich. Add 1 Tbsp. unsalted butter  and swirl so butter evenly coats bottom of pan and absorbs into sandwich. Cook until second side is golden brown underneath, about 4 minutes. Continue cooking, removing weight and turning sandwich as needed to ensure neither side gets too brown, until cheese is melted, 2–3 minutes more. Transfer sandwich to a rimmed baking sheet and repeat process with remaining sandwich and remaining 2 Tbsp. unsalted butter.

Step 6

Heat broiler to high (if broiler is in your oven, place a rack 1 slot down from the top). Spread mornay sauce over sandwiches to make about a ¼"-thick layer. (You might not use all of the sauce.) Broil until sauce is deeply browned in spots, about 3 minutes. (Watch carefully as sandwiches can go from browned to burned very quickly.)

Step 7

Transfer sandwiches to plates and mound some dressed greens on the side if desired.

Do Ahead: Sauce can be made 1 day ahead. Keep chilled.

Recipe notes