Created by Mikekey on September 4, 2015
Step 1: Beat eggs and milk together in a shallow soup bowl.
Step 2: Place 1 slice cheese, 1 slice onion, and 1 slice proscuitto on each of 4 slices of bread. Top each with remaining sliced cheese and another slice of bread.
Step 3: Carefully dip sandwiches into egg mixture to soak well.
Step 4: Heat half the butter in a large nonstick skillet over medium heat. When skillet is hot, add 2 sandwiches. Reduce heat to low and fry until bottoms are brown, about 5 minutes. Carefully turn sandwiches over with a spatula and cook another 5 minutes.
Step 5: Keep these warm while repeating with remaining 2 sandwiches.