Croissant Sandwich Recipe

Prepare croissants

Preheat oven to 350°F (175°C). Slice each croissant horizontally about three-quarters of the way through so the top remains attached. Arrange croissants on a baking sheet, open-faced. Lightly spread 1/2 tablespoon of room-temperature unsalted butter on the cut surface of each croissant bottom and top.

Toast croissants

Place the baking sheet in the oven and toast for 5–7 minutes, until the butter melts and croissant interiors are warmed and slightly crisped. If you prefer more golden tops, broil 30–60 seconds while watching closely. Remove from oven.

Prepare spread

In a small bowl combine mayonnaise (2 tbs), Dijon mustard (1 tsp), salt (1/2 tsp) and black pepper (1 tsp). Stir until smooth. Taste and adjust seasoning as desired.

Assemble sandwiches

Spread about 1 tablespoon of the mayo-mustard mixture evenly on the bottom half of each toasted croissant. On each bottom half layer 2 slices of deli ham, 1 slice of Swiss cheese, a lettuce leaf folded if needed, and 3–4 thin slices of tomato. If using optional avocado or fried egg, add them now. Spread a thin layer (about 1/2 tbs) of butter on the inside of the croissant top and place it over the filling.

Melt cheese (optional)

If you like the cheese melted, return assembled open-faced croissants (tops off) to the oven at 350°F (175°C) for 2–3 minutes until cheese just begins to melt. Then place tops back on.

Finish and serve

Cut each croissant sandwich in half if desired and serve immediately while warm. Offer hot sauce or additional condiments on the side.

Prepare avocado

If using avocado, slice half an avocado thinly and toss gently with a pinch of salt and a few grindings of black pepper. Add slices to each sandwich during assembly.

Fry eggs

To add fried eggs: heat a small nonstick skillet over medium heat with 1 teaspoon butter or oil. Crack eggs into the pan, season with a pinch of salt and pepper, and fry until whites are set and yolks reach desired doneness (about 2–3 minutes for slightly runny yolks). Place one fried egg on each sandwich during assembly.