Pour gelatin into a bowl and pour ½ cup of cold boiled water so that it swells.
Cut large mozzarella into cubes. Wash the basil in a bowl of water so that no sand from the leaves gets into the finished dish. Separate the basil sprigs, removing any tough stems. Chop the basil finely with a knife.
Heat the tomato juice over low heat until it boils, then cool it a little and add the swollen gelatin. Stir thoroughly. Gelatin will completely dissolve in hot juice. If this does not happen, reheat the mixture. But do not bring to a boil, otherwise the dish will not harden.
Add chopped basil, salt, pepper and olive oil to the tomato-gelatin mixture. Place the mozzarella balls into a silicone mold of a suitable size and fill with the tomato-gelatin mixture.
Place the mold in the refrigerator for 120 minutes. Before serving, remove the jelly from the mold and cut into cubes.
Serve this refreshing appetizer with tomato juice and caprese flavor to your holiday table alongside meat dishes. Bon appetit.