Put a large sauté pan over a medium flame and heat the oil. Add the rosemary and prosciutto and sauté until crisp, about 2-3 minutes.
Add the onion to the pan and cook until slightly softened, about 2-3 minutes.
Add the tomatoes and cook until they break down and release some juice, about 5 minutes.
Finally add in the chickpeas and toss for 2 minutes. Taste for seasoning and add salt and black pepper as desired.
Drop the pasta into a large pot of generously salted boiling water. Scoop out 1/2 cup of pasta water and set aside. Cook the pasta until al dente and drain.
Toss the pasta in the sauté pan with the sauce over medium heat for 2 minutes, adding the reserved pasta water if necessary.