Soak the gelatine in cold water. Peel and chop the garlic. Wash herbs and shake dry.
Bring cream, milk, garlic, herbs, 1/2 teaspoon salt and a little pepper to the boil. Let cool slightly and remove herbs. Squeeze out the gelatine and dissolve in it. Rinse 4 small moulds (each containing approx. 1/8 l; or use small cups) cold.
Pour in herbal cream and chill overnight.
Clean the arugula, wash it. Wash and quarter the tomatoes. For the marinade, mix vinegar, salt, pepper and some sugar. Fold in the oil. Turn out the panna cotta onto plates. Arrange lettuce and tomatoes around it and sprinkle evenly with the marinade.
Sprinkle with Parmesan cheese.