Steam the onion in oil. Add chickpeas, rosemary and potatoes and sauté briefly. Pour in the vegetable stock and simmer for 25 minutes. Puree in a blender. Salt and pepper.
Cook penne al dente.
Fry the zucchini in oil. Add cherry tomatoes and fry for about 3 minutes.
Mix the penne with the sauce, then serve with zucchini and cherry tomatoes.