frisa

Frise (or freselle, friselle, frisella, frisedde or fresedde) are twice baked rusks shaped like bagels, and hard enough to break your teeth—unless you dip them in sea water, as they used to do in Puglia.

Now they're more often topped with sun-ripened tomatoes, olive oil, fresh basil, salt, pepper and peperoncino shredded in oil.