Soak the chickpeas in water beforehand for at least 12 hours. After draining them and washing them under running water, put them in a pan soaked in cold water and let cook for about 3 hours.
Meanwhile, in a separate pan, let 1 garlic clove turn golden in half the quantity of oil, add the cherry tomatoes cut in two along with parsley and let cook for a couple minutes. Pour the sauté in the chickpeas pan, season with salt and complete the cooking. Blend some of the chickpeas within the same pan with the help of an immersion blender.
Let the diced bread toast in a non-stick pan by adding olive oil and rosemary.
While the Mafaldelle pasta cooks in a large pan, allow the other garlic clove (remove the sprout) to turn golden in the remaining olive oil. Remove the garlic after a couple minutes and add the clams to the same pan and a ladle of pasta cooking water. Cover with a lid and allow to cook. Once the clams are open, set a dozen of unshelled clams aside as we will use them to garnish the dish. Shell the rest of the clams and put them back in their cooking pan. Finally, add the Mafaldelle, the chickpeas and stir.
Serve by garnishing with toasted bread, unshelled clams and a rosemary sprig.