Preheat the oven to 375°F or 190°C and grease a 9×13-inch baking dish.
Heat the olive oil in a skillet. Cook the peppers and onion for about 5 minutes, until slightly softened.
Whisk the eggs, milk, garlic powder, salt, and pepper in a large mixing bowl.
Stir in the ham, cooked vegetables, parsley, and 1 1/2 cups of cheese. Pour the mixture into the dish and add the remaining cheese.
Bake for 35 to 40 minutes, until the center is set and the surface is lightly golden.
Cool for 10 minutes before slicing. Allow freezer portions to cool completely before wrapping.