Oil your skillet over medium-high heat. Add the ground turkey and minced garlic. Break the turkey apart and cook until browned and no longer pink, about 5-6 minutes.
In a small bowl, whisk together soy sauce, cornstarch, brown sugar, sesame oil, ginger, crushed red pepper flakes, and black pepper. Pour the sauce over the browned turkey.
Let simmer for 2-3 minutes, stirring occasionally, until the sauce thickens slightly. Taste and adjust seasonings or brown sugar as needed.