Step 2

Place a box grater in a large bowl. Grate the tomatoes on the largest holes, so that all that's left over is the tomato skins. Finely chop the tomato skins and add them to the bowl. Stir in the garlic and vinegar, then season to taste with salt. (If the tomatoes were very juicy, drain some of the juice, if necessary.) At this point, the mixture can be covered and refrigerated overnight.

Step 3

Preheat your broiler to high. Halve the ciabatta loaf lengthwise and cut each half into two-inch-thick slices. Place the halves cut side up on an ungreased baking sheet and drizzle the oil over the bread. Broil, checking frequently, until golden brown, about 3 minutes.

Step 4

Spoon the tomato mixture onto the slices of bread. Garnish with the oregano and flaky sea salt to taste and serve immediately, alone or as part of a tapas board.