In a large bowl crack 8 eggs and season with salt and pepper. Add in the cream. Whisk until all the ingredients are well mixed together.
Heat the olive oil in an ovenproof (20-25 centimeter) frying pan. Sauté the onions on medium-low heat until they have softened (about seven minutes). Add in the garlic, zucchini and tomatoes and cook for an additional five minutes. Add the parsley and chives and mix together. Then pour over the eggs. Cook over a medium low heat for 10-12 minutes until it is set. During this time, using a spatula move the edges of the frittata towards the center to create curds. Once the bottom of the frittata is set sprinkle with cheddar cheese.
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!