Fry the chorizo coins in some hot oil until they have crisped slightly and released all their paprika goodness. Turn the heat down a touch and add the chopped onion to soften it. Add the garlic and fry for a further minute. I have tried various herbs and spices with this dish including fresh rosemary, parsley, cumin and turmeric but, to be honest, the chorizo is so overwhelming there seems to be little point in trying to nuance it with other flavours. I add the chopped carrots at this stage to make sure they get coated in the spicy oil.
Season to taste with salt and pepper, give it a good stir and add the cubed potato or whatever veg you are using according to how long they will take to cook. Don’t forget the drained chickpeas, throw them in and simmer for 15 or 20 minutes or until it has reduced to a consistency you are happy with.