In a medium bowl, toss the flour with the grated cheese. Evenly spread the cheese over the bottom of the pie crust. Top the cheese with the diced ham. In a medium bowl, whisk together eggs, half and half, salt, pepper and dry mustard. Stir in the green onions.

Pour the egg mixture over the ham and cheese.

Cover the unbaked quiche with plastic wrap, then with foil, sealing the edges well.

Place the prepared quiche in the freezer. When ready to bake, preheat the oven to 400 degrees. Do not thaw the quiche!

Remove the foil and plastic wrap.

Place the foil around the edges of the crust to prevent burning.

Place the frozen quiche in the oven and bake for about 1 hour, or until the filling is set and the crust is golden brown.

To cook the quiche immediately (without freezing first), preheat the oven to 350 degrees and bake for 45 minutes to 1 hour.