STEP 1
Put the ancho chilli into a small bowl and pour over enough boiling water to cover. Leave for 10 minutes, drain, then discard the seeds and stem.
STEP 2
Heat the oil in a pan and cook the onion and celery with a pinch of salt for 10 minutes until soft. Add the garlic and cook for a minute, then add the spices and cook for another minute. Add the ancho chilli flesh, peppers and vegetable stock, and simmer for 15 minutes. Season, then use a stick blender to whizz until smooth. Keep warm.
STEP 3
Meanwhile, heat a griddle pan over a high heat, lightly brush the corn cobs with oil and season. Cook the cobs for 8-10 minutes, using tongs to turn them until really charred. Put onto a chopping board and allow to cool slightly. Turn a cob up on its end, then use a large sharp knife to carefully remove the kernels in a downward movement. Turn and repeat until all the kernels have been removed, then repeat with the other cob.
STEP 4
Stir the lime juice into the soup and add the sweetcorn. Divide between 4 bowls, scatter over the coriander and serve with lime wedges.