Preheat oven to 375 degrees, and set out pie crusts .
Brown hamburg and chopped onion in a skillet till it is cooked. Drain off any grease. Set aside
Take refrigerated pie crust and place crust on lightly floured waxed paper and use a floured rolling pin to flatten it slightly into a 10-inch circle. Use a biscuit cutter to cut 7 4-inch circles from the dough, you can reroll the dough scraps to get 3 more dough circles
Spoon 1 tablespoon of filling onto half of each circle, leaving about a 1/2-inch margin at the edge, put ketchup and mustard if you like both if you just like ketchup just put ketchup on the mixture. Sprinkle you favorite grated cheese on. I love velvetta so I just take a couple slivers on top it.
fold over and with wet fingers to press closed...use a fork to crimp the edges.
transfer the turnovers to a lightly greased baking sheet and poke each one twice with a fork for vents
Brush each one with milk, then bake for about 25 minutes or until golden brown. Serve warm.