These are like pizza-flavored mini-quiches using pepperoni as the crust in a mini-muffin pan. They also can be made without the pepperoni. You can use small amounts of whatever pizza ingredients you like.
Poke the pepperoni slices into the bottoms of the mini-muffin cups, or butter the cups well if you aren't using the pepperoni (I find that oiling the pans doesn't work as well).
Cream the cream cheese with a mixer until smooth and fluffy. Add eggs, garlic, and oregano, and beat until smooth.
Mix the rest of the ingredients in by hand.
Fill the muffin cups with the egg and cheese mixture.
Bake for about 15-18 minutes, or until lightly browned on top and set in center. Remove from oven, and cool for a few minutes (5-10), then run a knife around the top to loosen (I use a plastic knife for my nonstick pan). Remove to a plate.