Cut the mozzarella, zucchini and tomatoes into slices. Spread the zucchini and tomato slices on the shiny, oil-coated side of the aluminum squares (approx. 25 x 25 cm, one per serving). Sprinkle with black pepper and a little salt and chop the basil over the vegetables.
Cut each chicken breast fillet several times across with a sharp knife. Insert the mozzarella slices into the cuts. Arrange on the bed of vegetables and sprinkle with a little salt and pepper.
Now close the foils into small packages. Leave a little air above the meat and tear a very small opening in the upper part of the aluminum foil pocket to release small amounts of steam.
Bake the packets on a baking sheet in an oven preheated to 200 ° C for about 30 minutes. This goes well with pasta or rice.