01 -
Set oven temperature to 190°C and position rack in centre.
02 -
In a medium skillet over medium heat, melt 3 tablespoons butter. Add flour and whisk continuously for 30 seconds. Gradually add milk, whisking to prevent lumps, and cook until sauce is thickened, about 4 minutes. Remove from heat and incorporate Dijon mustard, salt, and nutmeg.
03 -
Spread softened butter on one side of each bread slice. Arrange four slices, buttered side down, on a parchment-lined baking sheet. Layer ham and half of the Gruyère over each. Top with remaining bread, buttered side up.
04 -
Transfer baking sheet to oven and bake for approximately 6 minutes or until bread turns golden and cheese melts.
05 -
Evenly spread béchamel sauce over the top of each sandwich. Optionally sprinkle with extra Gruyère. Broil for 3–4 minutes until cheese is bubbling and golden brown.
06 -
In a clean skillet, melt a small amount of butter or add oil over medium heat. Fry eggs until whites are just set and yolks remain runny, about 5 minutes.
07 -
Top each sandwich with a fried egg. Garnish with chopped chives, microgreens if desired, and season with freshly cracked black pepper. Serve immediately.