Roll out the puff pastry on baking paper and place on a wire rack. Spread thinly with mustard, sprinkle the grated Parmesan cheese over it and lightly season with salt and pepper.
Cut the tomatoes into slices and use them to cover the puff pastry evenly. Also distribute the olive slices evenly.
Mix the olive oil with the finely diced garlic, let it steep for a moment and spread over the tomatoes and olives with the garlic cubes.
Bake at 180 ° C with convection or 200 ° C top / bottom heat until the edges are golden brown. Make sure that the pieces of garlic do not turn black.