Whisk together the milk and the eggs. Add in the seasoning {garlic powder, salt, cayenne pepper}. Stir in the additional ingredients {green onions, cheese, herbs, etc.}.
Pour about 1.5 tablespoons egg mixture into mini muffin tins. Bake for 15-17 minutes until cooked through. Top with Greek yogurt, if desired.
Notes
These can be served warm or cold. Great to make ahead. This recipe is also easy to double or triple.