Mix first 6 ingredients in a medium bowl with a fork. Press into a 9" pie plate (or skip this step and buy a pre-made crust). Bake for about 10 minutes at 350 degrees.
In large skillet, cook onion and bacon until onion is tender and bacon is crisp. Drain on paper towels. Stir together eggs, sour cream, half and half (or milk), salt, and dash of nutmeg. Add bacon/onions, cheese, and spinach. Pour into hot, baked pastry shell and bake at 325 degrees for 45-50 minutes or until knife inserted near center comes out clean. Let stand 10 minutes before serving.