Puree the parsley, garlic cloves and olive oil and season well with salt and pepper.
Cut the potatoes and tomatoes into equal numbers of approx. 1 cm thick slices.
Place the potato slices on a baking sheet lined with baking foil and brush with the parsley puree. Place a slice of tomato on top and sprinkle with parmesan.
Gratinate in a preheated oven at 220 degrees for about 10 minutes.
Drizzle the tomato and potato snacks with a little balsamic vinegar and serve.