Mix together the black bean flour, white flour, baking powder, salt, water and oil in a medium size bowl. Turn out onto a lightly floured work surface and knead about 5 minutes, until elastic, add more water if needed. Let dough rest 15 minutes, divide dough into 6 equal portions and roll into balls. On a lightly floured surface, roll balls out until very thin and round.
Preheat a 10" or 12" nonstick skillet until hot, do not use any oil. Place tortilla round in skillet and cook each tortilla one at a time until golden brown on each side. Serve immediately. Tortillas can be kept warm in the oven as you cook remaining rounds. Tortillas can be stored in refrigerator up to 3 days or place cooled tortillas in a large ziplock bag and freeze for up to 3-4 weeks.
