Clean, wash and slice the carrots and cook in boiling broth for about 20 minutes. Puree with a hand blender and allow to cool. In the meantime, boil egg in boiling water for about 9 minutes until hard, rinse with cold water, peel and finely dice.
Soak 5 sheets of gelatine in cold water. Wash the dill, 1 bunch of parsley and chervil, dab dry and chop finely. Puree 350 g yoghurt and herbs, season to taste with salt and pepper. Squeeze out the gelatine, dissolve and stir into the herb yoghurt drop by drop.
Pour into a box mould (1 1/4 l capacity) rinsed with cold water and leave to cool for approx. 30 minutes. Soak 5 sheets of gelatine in cold water. Mix crème fraîche and carrot puree and season with salt and pepper.
Squeeze out the gelatine, dissolve it and stir into the carrot puree drop by drop. Pour onto the herbal yoghurt mixture in the box mould and refrigerate for another 30 minutes. Soak the remaining gelatine in cold water.
Mix the remaining yoghurt and sour cream and season with salt and pepper. Squeeze the gelatine, dissolve it and stir it drop by drop into the yoghurt sour cream. Pour onto the carrot puree in the box mould and chill for approx. 3 hours.
Clean, wash, quarter, seed and dice the tomato. Wash the remaining parsley, dab dry and chop finely. Mix vinegar, mustard, salt, pepper and sugar, add tomato cubes, parsley and egg and beat in oil.
Remove the mousse from the box with a sharp knife, turn over and serve on a plate garnished with lettuce leaves and chervil. Serve with extra vinaigrette. Baguette tastes good with it.