In a medium bowl whisk together the flour, yeast, baking powder, and salt. Add the mashed potato, yogurt, and most of the beer, mixing with a fork until until it has a smooth consistency. At this point depending on the consistency of your dough, you can add the rest of the beer. The texture should be moist, but not sticky. Cover the bowl with plastic wrap and let rise in a warm spot for 30 minutes (or can be refrigerated for up to 5 days).

Heat a cast iron skillet over medium heat. Grease the pan with a little olive oil.

At this point, you can shape your flatbread as small or large as you like, making it a little thinner or thicker as desired. Between 2 pieces of floured plastic wrap or parchment paper, roll a ball of the dough into a circle. You’ll want to remove the top piece of plastic wrap or parchment and carefully invert onto the palm of your hand. Remove the remaining piece of wrap or parchment and gently flip it into the pan. Alternately you can shape them by hand.

Cook until golden on bottom. Using a spatula, flip the bread over and cook on remaining side until golden brown. Remove to a rack to cool. Repeat with remaining dough.

Serve bread warm. If making a pan pizza, make your flatbread larger and top once the first side has cooked and you flip it over. Once the bottom is golden, you can place a lid over skillet to soften and melt the toppings. Alternately, you can place the cast iron skillet under the broiler for the last few minutes to melt the cheese and crisp up the top.