Peel and wash the potatoes and cook in boiling salted water for 15-20 minutes. Clean, wash and cut leek into rings. Blanch briefly in boiling salted water and rinse under cold water.
Cabanossi cut into slices. Cut the cheese into thin pieces. Pour corn and beans on a sieve and rinse briefly under cold water. Drain potatoes and cut into slices. Wash parsley, chop finely and sprinkle over the salad.
Mix all ingredients. Mix yoghurt and salad cream with mustard until smooth. Wash and drain the salad leaves. Line plate with lettuce leaves. Spread the lettuce on top. Pour a little salad cream on top.
Garnish with parsley. Add the rest of the salad cream.