Chilli and dumplings

Name: Chilli and dumplings
Ingredients: 1 tbsp. vegetable oil; 1 red onion, finely chopped; 1 red pepper, deseeded and finely chopped; 1 red chilli, deseeded and finely chopped; 750 g (1lb 11oz) lean beef mince; 2tbsp tomato purée; 1 tsp. smoked or normal paprika; 2 x 400 g tins of chopped tomatoes; 400 g tin kidney beans, drained and rinsed; Large handful fresh coriander, optional, roughly chopped; 100 g (3½oz) instant dry polenta; 100 g (3½oz) plain flour; 1 tsp. bicarbonate of soda; 150 g (5oz) sour cream; 1 large egg