In a non stick pan, fry the bacon until crispy, drain on paper towels. Crumble the bacon.
Pour out all but 2 tablespoons of bacon fat, add the onion and cook until tender but not browned, drain.
Preheat your oven to 190° C (375° F), arrange 6 tart shells on a baking sheet.
In a mixing bowl, add the crumbled bacon, onion, eggs, sour cream, cheese, salt, and pepper. Mix together.
Divide mixture among the tart shells.
Bake for 25-30 minutes, or until a knife inserted halfway from the edge to the center comes out clean.
Sprinkle with chives, serve and enjoy.