Heat a large skillet over medium-high heat. Add the ground beef, breaking it up with a spoon.
Add the minced onion, garlic, and grated ginger to the skillet and cook, stirring, until the beef is no longer pink and the onion is softened, about 6–8 minutes. Drain excess grease if needed.
Stir in the soy sauce, brown sugar, sesame oil, sriracha (if using), red pepper flakes, and black pepper. Cook, stirring, for 3–4 minutes until the sauce is slightly thickened and coats the beef.
Taste and adjust seasoning if desired. Serve the beef hot over cooked jasmine or white rice.
Optional: Garnish with sesame seeds or sliced green onions before serving.
