You may think that there are not enough ingredients when you layer everything. However, the egg will puff up when it cooks and the pie crust will shrink, leaving you with a perfectly even quiche.
You do not need to pre-bake or partially bake the pie crust. Keep an eye on the quiche in the last 10 minutes of baking. If you are concerned that the crust is getting too brown you can cover the edges with foil or a pie crust guard.