Recipe for mini quiches

I belong to a book group that meets once a month; as the joke goes, it's really a food and booze group with accompanying book discussion.  We have a gluten-free member, a vegetarian member, and a member who is allergic to nuts, and I enjoy the challenge of accommodating everyone's dietary needs while also making something that is edible and portable.  This month I made these mini crustless quiches in a muffin pan as an experiment, and they turned out pretty well.  I have no idea what the hell I'm going to do next month--any suggestions?

Mini Crustless Quiches

Makes 12

12 eggs
¼ cup milk
1 tablespoon prepared mustard
¼ teaspoon cayenne pepper
1 teaspoon salt
2 teaspoon dried oregano
1/3 cup frozen chopped spinach, thawed and drained
8 Kalamata olives, roughly chopped
2 tablespoons chopped sun-dried tomatoes
1 tablespoon finely diced red onion
4 tablespoons grated Parmesan cheese, divided
12 thin slices of fresh Roma tomato

Preheat oven to 350°F.  Generously grease a 12-cup muffin pan and set aside.

In a large mixing bowl, whisk together the eggs, milk, mustard, cayenne pepper, salt, and oregano.  Stir in the spinach, olives, sun-dried tomatoes, onion, and 3 tablespoons of the grated Parmesan.  Ladle egg mixture into muffin tin cups, distributing evenly and trying to get a variety of vegetables in each cup.  Place in the oven and bake 10 minutes.  Remove from oven--eggs should be almost set, and top each quiche with one thin slice of Roma tomato and a pinch of the remaining tablespoon of Parmesan cheese.  Return to oven and bake another 10 minutes, or until cheese is melted.

Mini quiches can be served warm or at room temperature, and they can be frozen for up to one month--just place on a cookie sheet in the freezer until hard, then put them all in a freezer weight zip-top bag.  To thaw, place in the refrigerator overnight or pop in the microwave for about 30 seconds each.