Step 1
To a large cast-iron skillet over medium-high heat, add 1 teaspoon of the oil. Add the bread and toast, pressing down with the back of a spatula so it cooks evenly, until well charred and deep brown on both sides, about 5 minutes total. (It’s okay to have a few blackened bits; if the edges are burnt, just slice them off.)
Step 2
Rub one side of the toast lightly with the garlic, then spread the cheese on top in a light, even layer. Season the tomato slices with flaky salt.