Heat sesame oil in a large skillet over medium heat. Add red onion, cook 2-3 minutes. Add garlic and ginger. Cook until fragrant, about 1 minute. Add ground pork and Sriracha. Cook and crumble until pork is cooked through and reaches an internal temperature of 160° F, about 7-10 minutes.
Add coleslaw mix, red bell pepper, carrots, soy sauce, sesame oil, rice wine vinegar, black pepper, and salt, to taste, and stir until well combined. Cook, stirring occasionally, until cabbage is tender, about 5 minutes.
Spoon pork-cabbage mixture in to a serving bowl. Drizzle with sauce of choice and garnish, if desired.
Optional for garnish: sliced green onions, sesame seeds, wonton strips.
Optional sauces: hoisin or duck sauce, sriracha, hot sauce, or sweet chili garlic sauce. For a creamy sauce, mix together Greek yogurt, sriracha, lime juice and salt to taste.