In a large bowl or plastic bag, combine whole bean flour, sorghum flour, tapioca starch, sugar, xanthan gum, yeast, salt and oregano. Mix well and set aside.
In a separate bowl, using a heavy-duty electric mixer with paddle attachment, combine water, vinegar and oil until well blended.
With the mixer on the lowest speed, slowly add the dry ingredients until combined. With a rubber spatula, scrape the bottom and sides of the bowl. With the mixer on medium speed, beat for 4 minutes.
Immediately pour onto prepared pans (see Notes). Spread evenly with a water-moistened rubber spatula. Allow to rise in a warm, draft-free place for 15 minutes. Bake in 400 °F (200 °C) preheated oven for 12 to 15 minutes or until firm. Spread with your choice of toppings. Return to oven and bake according to recipe topping directions.