Vegetarian chilli

Ingredients

• Vegetable oil (1 tbsp)
• 1 medium-sized onion
• Half a green pepper
• Half a red pepper
• 1 stick of celery
• 2 garlic cloves, peeled and crushed
• Tinned tomatoes (450g/14oz)
• A good pinch of dried oregano
• Cumin (½ tsp)
• Chilli powder (2 tsp)
• Black pepper (½ tsp)
• 1 tin of kidney beans (400g/8oz), drained
• 1 tin of cannellini beans (225g/8oz), drained
• 1 tin of black beans (225g/8oz), drained
• 1 fresh chilli, deseeded and finely chopped
• Frozen sweetcorn (140g/5oz) (optional)
• Sour cream and chopped chives to serve