Halve 1 large or 2 medium tomatoes. Grate the cut side of each half on the large holes of a box grater set over a medium bowl, stopping when only the tomato skins remain. Discard the tomato skins.
Strain the grated tomato through a fine-mesh strainer without pressing the solids. Return the tomato pulp to the bowl, add ½ teaspoon kosher salt, and stir to combine.
Brush both sides of the bread with 2 tablespoons extra virgin olive oil.
Heat a large skillet or grill pan over medium-high heat. Toast bread for 3–5 minutes per side until golden brown. Transfer to a plate.
Rub peeled garlic cloves on both sides of the toasted bread. Sprinkle with a pinch of flaky salt.
To serve, top each bread slice with a layer of the grated tomato, gently rubbing it into the bread with the back of a spoon. Top with anchovies and drizzle lightly with extra virgin olive oil.