Take the puff pastry out of the package, cut into 4 cm x 4 cm squares and place on a baking sheet lined with baking paper. Brush with a little milk. Place the tomato slices, leaving a small edge free, and pepper.
Put in the oven and bake for about 15-20 minutes, until the edges are lightly browned. In the meantime, mix the garlic cubes with the olive oil and basil.
Then sprinkle the finished baked squares with fleur de sel and brush with the garlic-oil-basil paste. Either serve immediately or enjoy cold.