Boil small potatoes in a uniform. Potatoes should not be larger than a quail egg. Cut into halves.
Blanch the string beans in boiling water for 5 minutes, drain the water and immediately put the beans in cold (or better, ice) water so that it retains its color. Drain the water and dry the beans on a napkin.
Cut small tomatoes into 4 pieces. Mix the vegetables in a bowl, add salt, shake the bowl.
For dressing, mix fresh cream, chopped parsley, grain mustard and olive oil.
Put the vegetables in a salad bowl and pour the dressing on top. This salad does not need to be stirred when serving. Everyone mixes it in their portion salad bowl.