Authentic Yakisoba (Japanese Stir-fried Noodles)

Name: Authentic Yakisoba (Japanese Stir-fried Noodles)
Prep time: 5 min
Cook time: 15 min
Total time: 20 min
Cuisine: Japanese
Ingredients: 140 g thinly sliced pork belly; ¼ onion (thinly sliced); 1 pinch salt and pepper; 50 g green cabbage (roughly chopped); 2 ptns ramen noodles; 1 tbsp cooking oil; red pickled ginger (benishoga) (optional topping); bonito flakes (katsuobushi) (optional topping); aonori (dried green seaweed powder) (optional topping); 1 tbsp Japanese soy sauce (koikuchi shoyu); 1 tbsp oyster sauce; ½ tbsp Worcestershire sauce; ½ tbsp sake (or white wine); 1 tsp tomato ketchup; 1 tsp toasted sesame oil; ½ tsp sugar; ¼ tsp curry powder; 1 pinch ground black pepper