Before dipping the tomato slices in the batter you could add some salt to make them give up some of their moisture, then dry them with kitchen paper. The batter, once fried, will thereby remain better attached to the slices.

The word ‘focaccia’ comes from the Latin ‘focaccia’, derived from the female noun ‘focacius’ meaning "baked" under the grill. Today it is also used to mean ‘crushed’.