Using the large holes of a box grater, grate the tomatoes with the skin on & discard the leftover skins.
Transfer the grated tomatoes to a fine-mesh strainer and let them drain until they're still moist but no longer swimming in their own juices. How much liquid you remove is ultimately up to you. Place the strained tomatoes in a bowl, season generously with kosher salt, stir to combine, and set aside.
Slice the bread into ¼-inch-thick slices. Lightly brush one side with olive oil, then toast until lightly golden and crisp around the edges.
Once toasted, cut the garlic clove in half and rub the cut side over the warm toast to infuse it with garlic.
Spoon the desired amount of grated tomatoes over the bread, then finish with flaky finishing salt and a drizzle of olive oil. If you're adding any additional toppings, add before serving. Serve immediately.