Clean the pork tenderloin, wash it and cut it into slices. Clean and wash the peppers and cut into pieces. Peel the onions, quarter them, cut into pieces and separate them into slices. Alternately thread the pepper pieces with the onion slices with the pork fillet slices onto the shashlik sticks (6 pieces). Heat peanut oil (5 tbsp) in a pan, slowly fry the pork fillet skewers on all sides until golden-brown and keep warm in the oven at 50 ° C until serving. A marinade / sauce made from plum sauce (4 tbsp), tomato ketchup (2 tbsp), sweet soy sauce (1 tbsp), light soy sauce (1 tbsp), dark soy sauce (1 tbsp), sweet paprika (½ teaspoon) and mild curry powder (½ teaspoon ). To serve, heat the marinade / sauce and drizzle over the pork fillet skewers.