Which New World food reached Italian cooking only after 1500?

The tomato, which arrived from the Americas after the Spanish conquest and was treated with deep suspicion for two hundred years. It belongs to the nightshade family, which contains several genuinely poisonous plants, and it was grown as an ornamental curiosity long before anyone in Europe would eat it.

There is a nice mechanical reason for the fear beyond the family resemblance. Wealthy Europeans ate off pewter, which is high in lead, and the acid in tomatoes leaches it out - so the people rich enough to be experimenting with novelties were the ones getting sick. Poorer people eating from wooden or ceramic plates had no such trouble, which is part of why tomatoes entered Italian cooking from the bottom of society upward.

The first Italian recipe using them appears in the late 1600s and they only became central in the nineteenth century. It is worth sitting with how much of a supposedly ancient cuisine is an import: no tomatoes, no peppers, no potatoes, no maize for polenta, no chocolate, no vanilla, no turkey before 1492 - and much the same is true of the chilli in Indian and Thai cooking, and the potato in Ireland.