Preheat your oven to 400 °F.
Lightly grease a 10-inch pie plate.
Sprinkle the crumbled bacon, shredded cheese, and diced onion evenly over the bottom of the pie plate.
Beat the eggs with the salt and pepper, then stir in the milk.
Add in the Bisquick and beat until smooth - it must be smooth to work!
Pour the liquid mix over the ingredients in the pie plate.
Bake in the preheated oven for 35 minutes or until a toothpick inserted into the center of the quiche comes out clean.
Let cool on a wire rack for 15 minutes.
Slice and serve!