Boil rice and water in a saucepan. Cover; cook on low 18 minutes. Rest covered off heat 10 minutes.
Heat 1/2 cup oil in a small skillet over medium to 350°F. Fry wonton strips in three batches, 30 to 60 seconds each, until lightly golden. Transfer to a paper-towel-lined plate.
Heat 1 tablespoon oil in a separate large skillet over medium-high. Brown beef 7 to 8 minutes, crumbling, until 160°F; transfer to a bowl.
Cook mushrooms and cabbage ribs in same skillet 5 minutes. Add garlic, ginger, cabbage leaves, and water chestnuts; cook 3 minutes until leaves wilt.
Return beef; add soy sauce, hoisin, and vinegar. Toss over high 2 minutes until hot and excess moisture evaporates.
Mix mayonnaise with sriracha. Divide rice and filling among four bowls; lightly drizzle with chili mayonnaise. Add crisp wontons just before serving.