Preheat oven to 400° F. If homemade dough, pierce all over with a fork. Freeze for 15 minutes. If purchased dough is frozen, thaw 15 minutes then pierce all over with a fork.

Bake the pastry shell until the edges are lightly golden, about 15 minutes. Transfer to a wire rack and let cool briefly. Reduce oven temperature to 375°F.

In a fry pan over medium heat, cook the bacon until crisp, about 8 minutes. Transfer to a paper towel-lined plate. Pour off all but 1 Tbs. of the fat from the pan, add the shallot and cook just until softened, about 1 minute. Stir in the spinach and cook until wilted, about 3 minutes.

In a bowl, whisk together the eggs, milk, salt, pepper and nutmeg. Add the spinach mixture to the bowl and stir to combine.

Sprinkle the bacon and cheese in the pastry shell. Pour in the spinach mixture. Bake until the filling is set and the crust is golden. Check at 30 minutes.

Transfer to a wire rack and let cool briefly. If freezing, set aside to cool. Wrap in aluminum foil and freeze for up to 2 months. To reheat, place the unwrapped quiche on a baking sheet and bake in a preheated 325°F oven until heated through, about 40 minutes.