Peel and roughly chop the onion and garlic. Finely mix egg yolk, mustard, garlic, onion and vinegar in the universal chopper or with the hand blender. Add oil slowly. Add yoghurt. Season to taste with salt, cayenne pepper and sugar. Add rosemary and green pepper and leave to stand for about 1/2 hour. In the meantime, clean and wash the mangetouts and blanch them briefly in boiling salted water.
Remove, rinse in cold water and drain. Clean and wash salads and chicory, pluck into bite-sized pieces and drain. Wash and clean the cucumber and cut into thin slices. Halve, clean, wash and cut the bell peppers into thin strips. Remove the rosemary sprig from the dressing. Mix salads, chicory, mangetouts, cucumber, bell peppers and salad dressing. Arrange on plates and sprinkle with the sprouts