Combine flour and salt. Cut in Crisco. Add water, a little at a time, with a fork. Knead to combine. Roll out dough on floured surface. Place dough in 9" pie pan and cut off excess crust that hangs over the edge. Crimp edges of crust.
Fry bacon in large skillet over medium-high heat until cooked and crisp. Remove from pan and place on plate lined with paper towel. Cool slightly and crumble.
Sprinkle bacon, shredded cheese and onion into prepared pie crust.
In a medium bowl, whisk together eggs, cream, half and half, salt, and cayenne pepper. Pour mixture slowly into pie shell over bacon, cheese and onion. (Pie pan will be very full. Transfer to oven carefully.)
Bake 15 minutes in the preheated oven. Reduce heat to 325 F. and bake an additional 30 minutes, or until a knife inserted 1 inch from edge comes out clean. Allow quiche to sit 10 minutes before cutting into wedges.