These mini frittatas are perfect for the in-between days! You can make a batch, chill them, and then just reheat in the microwave a few at a time when you want a light breakfast or lunch. They’re also perfect for a brunch buffet, as you can make them ahead of time and reheat to serve. Whatever amount of water you use to fill the wells is about how much egg mixture you will need for your muffin tins. Adjust the amount of eggs needed in this recipe accordingly.