Black bean corn tomato soup

Name: Black bean corn tomato soup
Cuisine: American
Ingredients: 2 red onions; 3 garlic cloves; 1-2 medium hot green chillies; 1 tsp ground cumin; 4 tbsp tomato purée; Handful coriander; 400g tin peeled plum tomatoes; 400g tin black beans or black eyed beans; 700ml vegetable stock; 400g frozen sweetcorn; 150g frozen peas; Juice of one lime; Sea salt; Black pepper; 1 small red onion; Finely grated zest and juice of one lime; 4-6 tbsp Greek style yogurt or soured cream; 1 ripe avocado; Squeeze of lime or lemon juice