Whisk flour and salt together in a medium sized bowl. In a separate bowl, combine oil and cold water. Pour liquids into the flour mixture, and stir until thoroughly combined. Press into a pie pan (it's nice to make little designs using a fork on the edges of the crust) and set in fridge while you're making the quiche.

Preheat oven to 350 degrees F.

Heat the olive oil in a medium saucepan on medium heat. Add onions and cook, stirring often until onions have softened slightly. Add mushrooms to the pan and cook for 5 more minutes, stirring occasionally. Remove from heat and set aside.

Crumble the pressed tofu into a large heat-safe mixing bowl. Add all other spices and the spinach to the bowl and mix thoroughly. Add in the cooked onion/mushroom mixture and stir. Lastly, add in the 3 vegan eggs and combine thoroughly.

Quickly pour this quiche batter into the prepared crust. If you'd like, add tomato and/or vegan cheese to the top of the quiche now and then bake for 30 minutes. Check occasionally to ensure your crust isn't getting too dark. If it is, put some foil over top of it. Test the quiche by inserting a knife and making sure the batter is cooked through and no longer liquidy.