Place under a broiler for two to three minutes until the cheese has melted and the top of the frittata has a beautiful golden colour.
Cut into circles or squares that are approximately the same size as the English muffin.
Assemble the sandwiches by placing a piece of the egg on the English muffin then topping it with your choice of prosciutto, bacon or ham.
Wrap each sandwich individually in plastic wrap, then place them all into a large plastic freezer storage bag. Great make ahead, can be frozen up to three months!