Place a piece of parchment paper into the slow cooker. Should be big enough to cover the bottom and up the sides a few inches.
Unroll the pie crust and add to the slow cooker. Try to place it as evenly as possible, even though the pie crust is round and slow cooker is oval, it should fit pretty well.
In a large bowl, add the eggs, half and half, salt, pepper and onion powder. Whisk until well combined. Stir in the ham.
Pour the egg mixture into the slow cooker. It's ok if a little bit spills over the quiche, it will still cook up fine.
Place the lid on the slow cooker.
Cook on HIGH for 2 hours and 10 minutes, the cooking time will vary, you will know it's done when the center is no longer jiggly.
Sprinkle over the cheese and replace the lid. Let the cheese melt, this usually takes less than 10 minutes.
Notes
How to Store:Store any remaining quiche in an airtight container and keep in the fridge for up to 3 days. Reheat on the stovetop or in the oven until warmed throughout.Can I use whole milk?Yes, whole milk works very well in quiche if you do not have half and half. Or you can use heavy cream.Variations:
Bacon JalapenoQuiche - Make the quiche completely different and use a pound of cooked and crumbled bacon and fresh diced jalapeno!