Soak wheat grains overnight. Pour off on a sieve and cook in the boiling vegetable stock for about 45 minutes. Clean and wash the watercress and remove the leaves. Wash the tomatoes and cut out the stem.
Cut the tomatoes into slices. Clean, wash and quarter the mushrooms. Peel garlic and press it through a garlic press or chop it finely. Mix garlic, salt, pepper and vinegar. Whip the oil into it.
Drain the wheat grains. Mix the salad ingredients with the marinade. Cut cheese into slices. Arrange salad and cheese on a plate.