Make pie dough the night before because it needs to chill in the refrigerator for at least 2 hours before using.
In a large bowl, beat/whisk the eggs, whole milk, heavy cream, salt, and pepper together until completely combined, about 1 minute. Cover and refrigerate egg filling until step 6.
Preheat oven to 375°F (191°C). Grease two 24-count mini muffin pans.
Working with 1 chilled pie dough at a time, roll into a large 12-inch circle. Cut rounds using a 2.5 inch cookie cutter.
Place the dough rounds into greased mini muffin pan(s). Press the dough flat into the bottom of the crevice and up the sides.
Evenly pour cold egg filling into each unbaked crust. Top evenly with add-ins, then sprinkle each with cheese.
Bake mini quiches until the center is just about set and edges are lightly browned, about 25-28 minutes. Allow to cool for 5 minutes before removing from the pan.
