This is where you’ll find that rare and coveted object: coal-oven pizza sold by the slice, and for pizza pilgrims, that alone is reason enough to leg it up to the original Patsy’s in East Harlem. To make the most of the experience, the thing to do is to consider this genre-defining slab, with its cooked-in aged-mozzarella-and-tomato topping, as a sort of amuse-bouche. Enjoy it in the dimly lit takeout storefront by the ancient oven before repairing to the red-sauce dining room next door. Here, under the incongruous gaze of a leaping marlin, you can tuck into an even better whole pie made with fresh mozzarella. It’s a well-cooked, exceptionally thin-crusted pizza, perfumed with the heady scent of 85 years of bituminous-coal-oven cookery.