Preheat oven to 375°F. Spray 12 cup muffin/cupcake tin with non-stick spray. Roll out the pie crusts and cut larger than the cupcake tin so it can go up sides. (It should be 3 ½ in wide) Fit the rounds in the cups of the prepared muffin tin, pushing the bottoms down and up the sides.
Spread 1 tablespoon cheddar cheese across bottom of each mini pie. Add 1 tablespoon ham and ½ tablespoon green onion on top of each. In a large bowl, whisk together the eggs, milk and black pepper. Pour evenly over the meat and cheese of each cup.
Bake for 35-40 minutes or until the middle is just slightly jiggly and top is golden brown. You can use a cake tester to test as well. Remove from oven and let sit for 5 minutes so it sets.
Don't skip spraying the muffin tins with cooking spray or you won't be able to get the quiche out.
Use store-bought pie crust. Yes you can make your own crust no problem, but these ham and cheese quiche are meant to be quick and easy to make. You won't miss making your own, but if you want to, I'd recommend this flaky quiche crust by Confetti & Bliss.
The perfect quiche ratio is 1 large egg to ½ cup milk. So if you want to make more or less, just keep that ratio the same. You want your quiche to be silky, not spongy.
Mix and match the ingredients you add in, but make sure they are dry. Wet ingredients can mess up your perfect liquid ratio.
Place the cheese on the bottom before adding the egg custard. By doing this you have a cheese layer on the bottom instead of it being mixed throughout which just adds to the flavor.
The best quiche jiggles slightly when you cut into, so don't overbake it. The quiche is done when the edges are set but the center still wobbles slightly.
Let the quiche sit in the muffin tins for at least 5 minutes before removing so it can set.
You can store the quiche in an airtight container for 2-3 days in the fridge or 2 months in the freezer. To reheat, cover with foil and bake at 325°F until cooked through.