Pre-heat oven to 350 F (177 C).
In a medium heat skillet, saute onions for ~5 minutes until translucent.
In a small bowl, mix ground flax and water together. Allow to sit for at least 5 minutes.
In a bowl, mix all ingredients together really well. Side note - you should not re-hydrate TVP for this recipe; the flax goo will provide enough moisture.
On a pizza pan or cookie sheet, dump "pizza dough" and begin spreading it out evenly making sure that it's tightly pushed together and there are no gaps. I like to use the back of a spoon for this.
Pre-cook in oven for 15 - 20 minutes.
Add any sauce, cheeze or toppings you're going to use.
Cook for another 15 - 20 minutes.
Allow to cool for at least 5 minutes before cutting, so that the crust firms up.