Preheat oven to 425 degrees. While oven is preheating, cook the Italian sausage and onion in a non-stick skillet, till completely cooked through. (5-10 minutes approx.). Drain grease.

In a separate saucepan, cook the spinach per pkg. instructions. Remove from heat, and drain really well to get excess moisture out. Add the cooked/drained spinach and the minced garlic to the skillet with sausage/onion mixture and mix well. Cook for an additional 1-2 minutes.

Prepare the unbaked pie shell by piercing shell with the tines of a fork - (this is to prevent the crust from creating air pockets and puffing up too much while baking)

Add cooked sausage, mozzarella and Parmesan cheese, garlic, onions, and spinach to the unbaked, prepared pie crust.

In a separate bowl, whisk together whipping cream, eggs, sugar, cayenne pepper, salt, and red pepper flakes, until well blended.

Pour egg mixture on top of the sausage/spinach/cheese mixture in pie crust. Gently mix ingredients together (I use a fork-be careful not to mix too hard or you will damage the crust. Just enough to blend the ingredients evenly together!)

Carefully put quiche into the preheated 425 degree oven. Don't spill it!

Bake at 425 degrees for 15 minutes, then reduce heat to 300 degrees and bake for an additional 35-40 minutes. (quiche is done when a knife comes out clean).

Remove quiche pan to a wire rack. Let it cool a bit, slice, serve... and enjoy!