Unroll the pie crust and use a 2-inch biscuit cutter, cut out 24 circles from the dough. Re-roll the dough as needed to get enough dough circles.
Spray a mini muffin tin with cooking spray. Press one dough circle into each muffin cup until it covers the bottom and sides of the cup. Bake for 5 minutes.
While the pie crusts pre-bake, whisk together the eggs, milk, salt, mustard, pepper, and nutmeg in a large mixing bowl.
Remove the muffin tin from the oven. Use a fork to poke holes in the bottom of any pie crust cups that bubbled up. Place the bacon crumbles in the bottom of each cup, dividing evenly. Then top the bacon with Swiss cheese, again diving evenly among the cups.
Whisk the melted cream cheese into the egg mixture. Pour 1 tablespoon of the filling into each pie crust cup over the bacon and cheese.
Place the muffin tin on top of a baking sheet (in case of spillage). Bake for 25 to 30 minutes or until the crust is golden and the filling is set.
Remove from the oven and allow to cool for 2-3 minutes in the pan. Then run a thin knife around the edge of each cup. Invert the baking sheet on the top of the muffin tin and flip. Remove the muffin tin.
Turn the mini quiches right side up and garnish with some fresh chives or chopped parsley and a little crumbled bacon. Serve warm or at room temperature.