• Preheat the oven to 375°F with a rack in the center position. Brush or drizzle olive oil onto one side of each of the bread slices. Place the bread slices on a sheet pan. Bake until the bread is lightly golden brown and toasty.
• Place 2-3 slices of smoked salmon on each, and top each with 2-3 tbsp of grated cheese. Top with the remaining slices, press gently, and put it back in the oven until the cheese has just melted.

Fry or Poach the Eggs

• Cook the eggs the way you prefer. Best method would be sunny side up fried eggs or slightly runny poached eggs. Aim for one egg per sandwich.

Bechamel Sauce

• Make the béchamel sauce. Warm the butter in a medium saucepan over medium heat until melted. Sprinkle in the flour and cook, whisking continuously, until the mixture is combined and the butter begins to bubble, about 30 seconds. Slowly whisk in the milk until smooth. Add the thyme and cook, whisking, until the sauce thickens, about 2 minutes more. Whisk in the mustard, salt, chipotle (if using) and nutmeg. Take the pain off the heat and discard thyme sprigs. 
• Evenly spoon the béchamel sauce over the sandwiches, then top with the remaining cheese. Broil until the cheese is bubbling and beginning to brown, 3 minutes. Top the sandwich with one fried egg.
• Garnish the sandwich with black pepper and chopped chives, if desired. And serve with bistro style spring salad.