Mix the ground turkey, egg, black beans, red bell pepper, mozzarella cheese, garlic powder, salt, and black pepper together in a bowl until blended; form the mixture into 4 patties.
Heat a large skillet over medium heat; cook the turkey patties in the skillet until cooked through and no longer pink the center, 7 to 10 minutes per side. An instant-read meat thermometer inserted into the center of a patty should read at least 160 degrees F (70 degrees C).
