Sift the cake flour, sugar, salt and yeast into a large bowl. Using a large jug, mix the warm water and oil together, then gradually add to the dry ingredients, stirring to form a soft dough. Turn out onto a floured surface and knead until smooth and elastic, about 8-10 minutes. Place the dough into a lightly oiled bowl, cover with a damp cloth and leave to prove until doubled in size, about 45-60 minutes.
Knock the dough back, roll it onto a floured surface, divide into 6-8 equal portions and roll into balls. Place on a tray, cover and allow to rise again for 15-20 minutes. Heat oil in a deep saucepan or pot over medium heat. Once hot, fry the dough balls in batches until golden brown and cooked through. Drain on a paper towel and set aside.
Heat the oil in a medium-sized frying pan over medium heat. Sauté the onion, green pepper and garlic until soft and fragrant. Stir in the smoked paprika, then season with salt and pepper. Add the pork mince and cook until browned, breaking it up with a wooden spoon as it cooks. Stir in the BBQ sauce, tomato sauce, and mustard. Simmer gently for 10-15 minutes until thickened and glossy. Adjust seasoning to taste.
Slice open the warm amagwinya and fill with the BBQ pork mince. Top with shredded cabbage and red onion rings and serve.
