Preheat the oven to 425° F.
Prepare a 13 x 18 inch baking sheet with parchment paper, set aside.
In a 2 cup measuring cup, mix together the plant based milk with the vinegar to make the vegan buttermilk, and set aside to curdle, about 5 minutes.
To make the egg substitute, add the equivalent of four eggs to a small bowl, blend with water, set aside until thick.
Add the flour to a medium sized mixing bowl and pour in the vegan buttermilk, egg substitute, salt, seasonings, and blend until there are no lumps.
Pour the batter into the lined baking sheet, spreading the batter evenly.
Place the baking sheet in the oven and bake for 30 minutes, checking with a toothpick or touching the top for sponginess.
If needed, continue baking for another 10 minutes if the bread isn't firm to the touch, testing around the middle of bread.
Once the bread is firm, remove from the oven.
If using as a sandwich bread, leave to cool then cut into squares, and store in the refrigerator.
But if using the bread as a pizza crust, spread the sauce on, add the topping of your choice, and place back into the oven for about 8 minutes or until the cheese has melted.
Remove the flatbread pizza once done to your likeness, cut into squares, and enjoy.
