Roll out the pie dough on a floured surface. Gently lay it in a deep-dish pie pan and press it into the grooves of the pan. Cut off the excess. Set aside.
Chop up the bacon into bite-sized pieces.
Fry the onions in the butter in a heavy skillet over medium-low heat until deep golden brown, 12 to 15 minutes.
Meanwhile, mix the eggs, cream and some salt and pepper together in a large bowl. Add the bacon, onions and cheese and stir to combine.
Pour the mixture into the pie shell. Cover lightly with aluminium foil, place on a sheet pan and bake for 45 minutes.
Remove foil and bake until the quiche is set and the crust is golden brown, about 10 minutes more.
Allow to sit for 10 minutes. Fit for a king or a cowboy.
Pam's Pie Crust:
Lightly mix 2 cups of the flour with the salt and sugar in a mixing bowl or a food processor. Cut the butter into the flour using a pastry cutter or by pulsing the food processor. (The mixture should look like large crumbs and begin to cling together in clumps.)
Add the remaining 1/2 cup flour and mix lightly or pulse two or three times so as not to overmix the flour. Tip into a bowl. Sprinkle 1/4 cup cold water over the dough and mix with your hands or a wooden spoon until the dough holds together. Shape the dough into two discs.
Wrap the dough in plastic wrap and store in the fridge until ready to use. It can also be frozen for up to 6 months.