Preheat your oven to 425°, and prepare pie crust (directions below, or use your favorite pie crust.)
In a bowl, whisk together the eggs, milk, mustard, salt and pepper. Set aside
Sprinkle the bacon in an even layer in the pie crust, and top with tomato and pineapple.
Top with the cheese, then pour the egg mixture over the top of the fillings in the crust.
If you are using a glass pie pan, bake in the lower third of your oven so that the bottom, so that the bottom crust gets crisp before the edges get too browned. Bake for 30-35 minutes, or until crust is browned and the eggs are set. If the edges of the crust begin to brown too quickly, cover with small pieces of foil.
Cool slightly before serving.
For the gluten free pie crust
Lightly grease a 9" pie pan (note: a metal pie pan is recommended. Whisk together the flour blend, xanthan gum, and salt.
Sprinkle the cold butter pats over the flours and cut into the flour mixture with a pastry blender until its crumbly with some larger pea-sized chunks.
Whisk the egg and vinegar together until very foamy.
Mix egg mixture into the dry ingredients and stir until the mixture holds together. Add an additional 1 to 3 tablespoons cold water if necessary.
Shape into a ball and chill for an hour, or up to overnight. Allow the dough to rest at room temperature for 10 to 15 minutes before rolling.
Roll out the dough on a piece of plastic wrap or silicone mat that's been sprinkled with gluten-free flour until it's about an inch larger than the pie plate on all sides. Invert the crust into the prepared pie pan and press into the pan. Tuck in the edges, trim the excess, and crimp the edges.