These make the best easy breakfast!
Preheat the oven to 350 degrees. Spray muffin tins with cooking spray.
Place an equal amount of chopped green peppers, tomatoes and onions into each muffin cup.
Beat eggs, milk, salt and pepper in a large bowl. Pour an equal amount of egg mixture into each muffin cup.
Top with equal amounts of shredded cheese.
Place in oven and bake until golden brown, about 25 minutes. Eat warm or let cool in pan and then remove and store in a sealed container in the refrigerator for up to four days.