Tortilla Soup

Heat the oil in a saucepan. Add the onion and garlic and cook over a medium heat for 5-8 minutes, until just softened. Add the tomatoes and salt and cook for another 5 minutes.

Stir in the chicken stock. Bring the liquid to the boil, covered, then lower the heat and simmer for about 15 minutes.

Meanwhile, for the garnish, trim the tortillas into squares, then cut them into strips.

Put a 1 cm (1/2 in) layer of oil in a frying pan and heat until hot but not smoking. Add the tortilla strips, in batches, and fry until just beginning to brown, turning occasionally. Remove with a slotted spoon and drain on kitchen paper.

Add the carrot to the soup. Cook, covered, for 10 minutes. Add the courgette, chicken and chillies and continue cooking, uncovered, for about 5 minutes, until the vegetables are just tender.

Meanwhile, peel and stone the avocado. Chop into fine dice.

Divide the tortilla strips among four soup bowls and sprinkle each one with the avocado. Ladle in the soup, then scatter the onions and coriander on top. Serve immediately.