Slice sausage and stir-fry until lightly browned. Add chopped red onion, red/yellow bell peppers, and green chilies and cook for 2 3 minutes, keeping the vegetables slightly crisp. Add ketchup, sweet chili sauce, soy sauce, oyster sauce a little hot sauce, minced garlic, black pepper, and a small splash of water. Toss everything over high heat until the sauce becomes thick and glossy and coats the sausage and vegetables. Serve hot with rice or noodles.