Brown ground beef in a large nonstick skillet, crumbling it as it cooks. When it is about halfway cooked, add bell pepper and onion. Continue to cook until no pink is left in the beef.Drain off any grease.
Add garlic and ginger and cook for 1 minute.
In a small bowl, whisk together soy sauce, rice wine vinegar, water, brown sugar, sesame oil, and red pepper flakes.Whisk in cornstarch.
Add sauce to the ground beef mixture and simmer until thickened.
Stir together broccoli slaw and dressing or sauce.
Divide ground beef mixture between the buns, top with slaw, peanuts, and cilantro. Serve.