In a bowl, mix the flour, black pepper, red pepper, garlic powder, eggs, and beer. The mixture should resemble pancake batter.
Heat the oil in a skillet over medium heat. Dip tomato slices in the batter to coat, then fry in the skillet 5 minutes on each side, until golden brown. Drain on paper towels and season immediately to taste with a sprinkle of salt. Eat while hot.