This is a cross between a hearty soup and a main meal. Put the finely chopped onion, celery and garlic into a saucepan with a little olive oil and the rosemary (if using) and cook as gently as possible, with the lid on, for about 15-20 mins, until the veg is soft, but not browned.
Drain the chickpeas well and rinse in cold water. Add to the pan and cover with the stock. Cook gently for half an hour then, using a slotted spoon, remove half the chick peas and put them to one side in a bowl.
Puree the chickpea mixture in the pan using a stick blender. Add the reserved whole chickpeas and the pasta, season and simmer gently until the chickpeas are tender and the pasta is cooked.
You can thin the soup down with a little boiling water if desired. Check the seasoning and serve drizzled with good quality olive oil and sprinkled with the parsley or basil