A properly made Croque Monsieur, or rather the Croque Madame version with the egg, is a wondrous thing. Only the French could take something basic like a ham egg and cheese sandwich and elevate it to a culinary masterpiece.

The traditional version uses ham, bechamel, dijon mustard, and Gruyère, on pan de mie or brioche. It’s rich and gooey, savory and creamy. But getting the proportions just right can tricky, and since I’m not a big fan of ham and happened to have some leftover roast chicken, decided to mix it up a bit.

Ingredients (for 2 sandwiches)

• 2 challah rolls (or 4 slices challah or brioche or other thick egg bread)
• 1 TB butter
• 1 TB flour
• 1 cup milk, warm
• 1 tsp Dijon Mustard
• 4 oz grated Gruyere or cheddar
• 4 oz Raclette or Gruyere, sliced or shredded
• Roast chicken, or ham

Directions

1. Preheat oven to 375F
2. Make the bechamel: in a small saucepan, melt the butter, and whisk in the flour. Heat the milk in the microwave for 1 minute to warm it up, and add it slowly to the roux while whisking to avoid lumps. Cook for about 5 minutes over med-low heat until slightly thick.
3. Add the mustard and grated cheese to the sauce, and stir until completely incorporated. Season to taste with salt and pepper. Set on low burner to keep warm.
4. Cut the roll in half, and slather both insides with the cheesy sauce. Add slices of meat, then top with the sliced/shredded cheese, and put on the top of the roll (or second slice of bread). Spread on another general dollop of the sauce to coat thoroughly, and top with a final slice of cheese.
5. Bake in the oven until heated through and cheese is melted and starts to brown.