Crust. Process flour and butter into food processor till the mixture looks like coarse sand. Add salt. Add the liquid one tablespoon at a time until dough just holds together. Make a ball of dough; wrap it in a plastic wrap; chill for an hour in the refrigerator.
Filling: Saute onions in a tablespoon of butter over medium high heat till it's soft. Set aside to cool. In a medium bowl, combine cooked onions, spinach, 2 eggs, sour cream, half of cheeses (cheddar, pepper jack, and parmesan) and artichoke hearts; season with salt and pepper.
Using 3 eggs, separate egg whites and yolk; beat the egg whites until stiff. Slowly fold in the egg whites to the eggs yolks.
Fold in half of the beaten eggs to the rest of the filling. Reserve half of the beaten egg whites for topping.
Assemble the quiche.Combine the remaining cheeses (cheddar, pepper jack, parmesan) in a bowl. Roll out the dough and fit into buttered ramekins.
Layer the crust with cheese; then spoon filling over the cheese and top with the remaining beaten egg whites.
Bake in a 375F degrees preheated oven for 30-35 minutes.
