Whole Wheat Croque-Madame with Lox and Arugula 

Instructions

1. Bring a large pot of salted water to a boil. Add the arugula and blanch for 3 minutes. Transfer to a colander and cool under cold water. Drain and squeeze out the remaining liquid. Set aside.
2. In a medium saucepan, melt 2 tablespoons of the butter over medium-low heat. Add the flour, and with a whisk, stir constantly for about 3 minutes. Slowly whisk in the milk to avoid lumps, then add the nutmeg, salt, and pepper, and continue to stir for about 5 minutes, being careful not to brown. Stir in 1 tablespoons of the Gruyere until it melts. Remove the sauce from the heat and cover with wax paper to prevent drying out. 
3. Set an oven rack a few inches from the top and heat the broiler to medium high. 
4. Arrange the bread slices on a plate and spread about 1 teaspoon of the sauce over 2 of the slices and sprinkle with remaining cheese. Spread 1 teaspoon of mustard on the remaining slices of bread and divide the ham, lox, and arugula over each piece. Carefully flip the slices with gruyere over the slices with ham to close each sandwich.
5. Lightly grease a foil-lined medium baking pan with cooking spray. Set aside. 
6. Lightly grease medium skillet with cooking spray over medium-low heat. Cook the sandwiches for 2 minutes on one side until golden brown. Flip sandwiches over and cook for another 1 to 2 minutes longer, until golden. Transfer sandwiches to baking pan.
7. Spread remaining sauce over each sandwich. Broil on the top rack for 2 to 3 minutes, until the sauce bubbles and lightly browns. Remove from the broiler and tent with foil to keep warm.
8. Meanwhile, lightly grease a medium skillet with cooking spray over medium-low heat. Crack two eggs at a time into skillet and fry until the whites have set, but the yolk is still runny. Transfer to plates and repeat with remaining eggs.
9. Cut each sandwich in half to make four half sandwiches. Top sandwich halves with a fried egg. Serve immediately.