Toss beef, soy sauce, 2 tsp. rice wine, cornstarch, sesame oil, ginger, salt, and pepper in a bowl.
In a separate bowl, combine remaining rice wine, the chicken broth, oyster sauce, and dark soy sauce.
Heat 1 tbsp. peanut oil in a 12" wok or nonstick skillet over high; cook black beans and garlic until fragrant, 30 seconds.
Add beef in a single layer and cook, without stirring, about 1 minute; stir, and cook 2 minutes more.
Transfer beef to a plate.
Heat remaining peanut oil and cook onions until translucent, 2 minutes.
Add broccoli and stir fry until heated through, 2 minutes; add beef and its juices plus reserved sauce.
Cook an additional 1-2 minutes.
Serve with rice.
