Put stock, cream,zest and garlic into a frying pan and boil vigorously until reduced to about half. The sauce needs to be fairly thick to coat the pasta. It will take 10-15 minutes. Be careful not to let it boil over!
Add pepper, 1/2 cup parmesan, spinach and most of the basil, reserving some for the top.
Cook gnoochi according to packet directions and drain. Add to the sauce.