Chilli bean bake with soured cream mash

Name: Chilli bean bake with soured cream mash
Ingredients: 2 onion, chopped; 1 tbsp olive oil; 2 tsp each ground cumin and dried thyme; 2 tbsp mild chilli powder; 1kg lean minced beef; 2 x 400g can chopped tomatoes; 2 x 400g can kidney bean, rinsed and drained; 2 x 330g can sweetcorn, drained; 3 mixed pepper, chopped into chunks; 2 tbsp white or red wine vinegar; 2 tbsp brown sugar; 1 beef stock cube; 1.8kg potatoes, chopped into large chunks; 300ml pot soured cream; 2 x small bunches chives, snipped; 100g cheddar, grated