Heat the olive oil in a heavy based casserole pan and fry the chorizo over a medium heat until slightly browned. Remove from the pan with a slotted spoon and set to one side.
Add the onion and leek to the pan and fry for a few minutes, stirring all the time. Reduce the heat, cover and leave to sweat for 5-10 minutes, stirring occasionally. Keep an eye on it because you don’t want them to brown.
Add the garlic, chilli and red pepper, cover again and leave to sweat for a further 5 minutes.
Put the chorizo back into the pan along with the chickpeas and enough stock just to cover. Season. Bring back to the boil, cover and simmer for 10 minutes or until the vegetables are tender. At this point you can simmer with the lid off to reduce the stock if you want a thicker sauce.
Add the chicken and poach for a few minutes until cooked. At the last minute check the seasoning and add the parsley.