Preheat the oven to 425 degrees F.
Meanwhile, in a large bowl, mix together the eggs, milk, and cheese until well combined and frothy.
Lightly spray a pie plate/pan with non-stick cooking spray. Roll out the pie dough to 12 inches in diameter and fit in a pie plate. Don't worry about making it perfect here, wet fingertips can fix the imperfections in the crust and you can press it into the mold so that the bottom of the pie plate is covered, and the sides are about 1 inch tall.
Pour the filling into the pie dough. Sprinkle the cubed ham into the quiche. Bake, uncovered, until the filling is set and the crust is golden brown, 25-30 minutes. **You want your eggs to be set; however, you want it to have a bit of a wobble to it as it comes out of the oven. It continues to cook and set as it rests-- and the wobble will ensure it has a silky, not rubbery, texture.
Remove from oven and let cool for 5-10 minutes before slicing. Serve and enjoy!