Pork Cabbage Stew

3 tbsps sunflower oil
750 g Pork rashers
½ onion, sliced
1 tbsp barbecue spice
2 tbsps medium curry powder
50 g tomato paste
3 cups water
½ cabbage, cut into small chunks
½ yellow pepper, diced
1 chicken stock cube
2 potatoes, cut into cubes