In a large nonstick skillet, warm 1/2 tablespoon of the oil over medium-high heat. Add the sirloin, garlic, and ginger. Cook, stirring, for about 5 minutes, or until the meat is cooked through and no longer pink. Transfer to a plate.
Add the remaining 1/2 tablespoon oil and the broccoli to the skillet. Cook, stirring, for 3 minutes. Add the soy sauce, hot-pepper sauce, and meat mixture. Serve sprinkled with the scallions and cilantro (if using).