In a medium, shallow bowl, whisk together flour, cornstarch, salt, chili powder, and black pepper. Slowly stir in some beer creating a smooth and stirable paste. Add more beer (about 1/2 cup more) to create a batter than is the consistency of pancake batter. I didn’t use the entire 12 ounces of beer. I had about 1/4 cup of beer left in the can.