Croque Monsieur Recipe

Preheat oven to 425°F (220°C). Toss halved baby potatoes with olive oil, thyme, kosher salt, and black pepper on a rimmed baking sheet in a single layer.

Roast for 20–25 minutes, turning once halfway, until golden brown and crisp at edges. Keep warm while you make the sandwich.

In a small saucepan over medium heat, melt 2 tbs unsalted butter until foaming but not browned.

Add 2 tbs flour and whisk constantly to form a smooth roux; cook 1–2 minutes without browning to remove raw flour taste.

Slowly pour in 1 cup whole milk while whisking continuously to avoid lumps. Continue to cook, whisking, until the sauce thickens to a creamy, coat-the-back-of-a-spoon consistency (about 3–5 minutes).

Season with 1 tsp salt, 1 tsp black pepper, and a pinch of freshly grated nutmeg. Remove from heat and set aside. If it cools and thickens too much, whisk in a tablespoon of warm milk to loosen.

Preheat broiler to high and position rack about 6 inches from the heat source (or preheat a heavy skillet over medium if not broiling).

Spread 1 tbs softened butter on the outside of each challah slice (both slices' outer faces). If using, spread 1 tsp Dijon mustard on the inside of one slice.

On the inside of one slice, layer the ham (3 slices) and 2 oz Comté. Top with a thin layer (about 2 tbs) of béchamel sauce. Close with the second slice of bread, buttered side out.

If you are doing the egg-dipped option: whisk 1 large egg with 1 tsp milk, pinch salt and pepper in a shallow bowl. Quickly dip the assembled sandwich, one side at a time, into the egg wash so the exterior soaks a thin layer. Allow excess to drip off.

To cook: place sandwich on a hot skillet buttered side down (or on a baking sheet if broiling). If using skillet, cook 3–4 minutes per side over medium heat pressing gently with a spatula until golden and cheese begins to melt. If broiling, place on baking sheet and broil 2–4 minutes per side until top is bubbly and golden — flip once and sprinkle the top with the reserved 1 oz grated Comté before finishing so it melts and browns.

If you did not broil and want the top browned, after flipping the sandwich, spread a thin layer of béchamel on top, sprinkle with the 1 oz grated Comté and move to a preheated oven or under the broiler briefly to melt and brown (1–2 minutes).

Remove sandwich from heat and let rest 1 minute. Slice in half on the diagonal.

Plate the croque monsieur with a generous spoonful of any remaining béchamel on the side or drizzled on top. Arrange roasted potatoes alongside.

Garnish potatoes and sandwich with chopped parsley if desired. Serve immediately.