Step 1

Remove the husks and silk from the corn cobs, then cook the corn in a saucepan of boiling water for 10-12 minutes. Lift out corn and cool; reserve the cooking water.

Step 2

As soon as the corn is cool enough to touch, slice off the kernels with a sharp knife (reserve the kernels). Return the cobs to the pan of cooking water and bring back to the boil.

Step 3

Boil gently for 30 minutes, then discard the cobs. This is the stock.

Step 4

Meanwhile, put the onion, garlic, ginger and oil in a saucepan. Cook gently until the onion is tender and lightly golden, stirring occasionally; don't let the onion burn.

Step 5

Stir in the allspice and cumin, then pour in 1 litre of corn stock and add 1 teaspoon salt. Bring to a gentle boil, then cook for 10 minutes.

Step 6

Halve and pit the avocados, remove the skin and chop the flesh. Squeeze over the juice of 1 lime and sprinkle with sea salt. Cut the other lime into wedges.

Step 7

Dish up the soup and add a tumble of corn and avocado to each bowl. Sprinkle with coriander and sliced red chilli, and serve with lime wedges.