Lay out the layers in the serving ring;
tomatoes
tuna
Basil
mozzarella
Basil
tomatoes.
Sprinkle with ground pepper and you can serve!
P.S. If you do not have a serving ring for salads, you can use a plastic milk bottle, pre-cut it. Or take a square box of kefir, doing the same manipulations with it)). Be sure to smear the inside of it with vegetable oil: the salad will slide and will not crumble when removed from the mold.