Clean the salad, wash and drain well. Clean and wash radishes and mushrooms. Wash or peel cucumber. Slice radishes, mushrooms and cucumber into thin slices.
Wash the fillet, dab dry and season with salt and pepper. Heat oil in a coated pan. Fry the meat in it all around for about 4 minutes. Take it out, wrap it in aluminium foil and let it rest for about 5 minutes.
Wash the chives and put some stalks aside for garnishing. Cut the rest into fine rolls. Mix with yoghurt, mayonnaise and lemon juice. Season the sauce with salt, pepper and a little sugar.
Pluck the salad into bite-sized pieces. Arrange on plates with the remaining salad ingredients and dressing. Cut the lamb fillets into slices at an angle and arrange on top. Garnish with remaining chives.
It goes well with bread.