Beat 1st 7 ingredients together.
Sprinkle bacon over the bottom of the unbaked piecrust. Add spinach and onion & red pepper if desired.
Pour liquid ingredients over all. Be sure cheese is covered with the liquid mixture.
Bake 15 minutes at 400 degrees, then lower temp to 350 degrees for 35 minutes.
Let rest at least 10 minutes before cutting into wedges.
May top with fresh tomato slices to serve.