Mix the dry ingredients (1 1/2 cups flour, 1/4 tsp baking soda, 3/4 tsp salt) in a bowl then pour in 1/2 cup oil and 3 tbsp boiling water. Mix well until it forms a ball.
Place the ball of dough on a piece of parchment paper and push it flat. Cover with the second piece of parchment paper.
Use a rolling pin to roll the dough flat between the parchment, then peel off the top sheet. Use the bottom piece of parchment to help you flip the crust onto the pie dish and peel off the second piece of parchment.
Pinch around the edges forming the pie crust into an even edge.
Make the vegan quiche filling
Preheat your oven to 400°F (200°C).
Dice 1 medium onion and saute it in 1 tbsp of oil over low heat until translucent.
Add 2 cups diced mushrooms sprinkle with 1/2 tsp salt and continue to saute until they begin to release their juices.
Add 5 oz of baby spinach and stir for a few minutes until the spinach just barely wilts, then turn off the heat.
Break up 2 packages of tofu into smaller pieces so it fits in your food processor. (You may have to do this in 2 batches if you don't have a large food processor).
Add 1/2 cup nutritional yeast, and 1/4 cup melted margarine, 2 tsp. salt, and 1/2 tsp pepper, to your food processor and blend. (It will turn into a crumbly grainy mixture).
Slowly add 1/4-1/2 cup soy milk, 1 tbsp at a time, blending between each tbsp until the tofu mixture turns from crumbly to a very thick paste. (If you don't use the high protein tofu, you may not need much milk).
Add the tofu mixture to the sauteed veggies along with 2/3 cup vegan cheese, and 2/3 cup vegan bacon bits. Mix well.
Pour the combined tofu-veggie mixture into your formed pie crust and pack the tofu down firmly and evenly in the pie dish.
Bake at 400°F (200°C) for 1 hour.
Brush the top of the quiche with an additional tbsp of melted margarine if desired for a shiny glow.
Let it cool for about 10 minutes before cutting to allow it to set a little and firm up.
Notes
This makes a large quiche! It fills a 9-inch pie dish to the top.
If you are using a small ready-made pie crust, you may want to cut the recipe in half.
You can find packs of 2 ready-made vegan pie crusts in tins at most grocery stores. This recipe fills those 2 ready-made crusts perfectly.
To make crustless quiche muffins
Follow the instructions to make the quiche filling.
Spray muffin tins with a little oil and then fill with the tofu veggie mixture.
Bake the quiche muffins at 400°F for 25 minutes. (Allow them to cool a little before taking them out of the muffin tins).