Ingredients:
Sourdough bread, sliced to ½ inch thickness
Kosher salt and freshly grated black pepper
1 whole egg
1 teaspoon unsalted butter
Parmigiano-Reggiano, shredded
1 slice Prosciutto
Baby arugula, as needed

Instructions:
Preheat the oven to 350F.
On a sheet pan lined with foil, place the bread slices side by side and drizzle lightly with EVOO, season lightly.  Once the bread (crostini) is lightly toasted, remove from the oven and set aside.  In a medium non-stick pan over medium heat, add 1 teaspoon butter and heat until just beginning to brown.  Crack the egg into the pan, season lightly, and add 1 teaspoon cheese.  Cover the pan (glass lids are good for this recipe) and allow to cook until the white is set but the yolk is not. 
To serve:  On one slice of crostini, place the slice of prosciutto followed by a few leaves of arugula, the hot egg, and top off with more cheese if desired.  Serve immediately.
Serves 1