Prepare the Scallions: Chop the scallions and separate the white portions from the green portions, reserving the green portions for later.
Prepare the Aromatics: Peel and mince the ginger root, then mince the garlic.
Heat the Pan: Lightly coat a frying pan with cooking spray and preheat it over medium heat.
Cook the Aromatics: Add the white parts of the scallions, minced ginger, and minced garlic to the heated pan. Cook for about 5 minutes, stirring as needed, until the mixture becomes fragrant. Brown the Beef: Add the 96/4 extra-lean ground beef to the pan. Break it apart with a wooden spoon and cook for about 5 minutes, or until the beef is no longer pink. Steam the Cabbage: Add the shredded cabbage to the pan and cover with the lid. Allow the cabbage to steam until it becomes wilted. Add the Water Chestnuts: Chop the canned water chestnuts and add them to the pan with the cabbage and beef mixture.
Mix the Sauce: In a small bowl, combine the hoisin sauce, reduced-sodium soy sauce, rice wine vinegar, sriracha, and sesame oil. Stir until the ingredients are evenly combined. Combine the Filling: Once the cabbage has wilted, pour the prepared sauce into the pan. Stir thoroughly so the sauce coats the beef, cabbage, and water chestnuts. Simmer the Mixture: Continue simmering the sauced beef mixture briefly to help distribute the sauce evenly throughout the filling.
Finish the Filling: Stir in the reserved green parts of the scallions and the sesame seeds.
Assemble the Wraps: Spoon the warm beef filling into lettuce leaves, using about 3–4 lettuce leaves per serving. Add extra sriracha on top if desired.