Mexican Tomato and Bean Soup

Ingredients

• 2 tablespoons olive oil
• 2 red onions, finely chopped
• 3 garlic cloves, finely chopped
• 1-2 medium-hot green chillies, such as jalapeño, deseeded and finely chopped
• ½ teaspoon ground cumin
• 600ml vegetable stock
• 200ml roasted tomato sauce or passata
• 400g ripe tomatoes, cored, deseeded and finely chopped
• 400g tin black beans or black eyed beans, drained and rinsed
• A handful of oregano, chopped
• A pinch of sugar
• Juice of 1 lime
• A small handful of coriander, roughly chopped
• Sea salt
• freshly ground black pepper
• 4-6 tablespoons soured cream (optional)