Puree the peaches in the juice, except for one half. Stir in peach nectar and divide into 4 deep plates. Wash the lemon thoroughly, dab dry and grate the peel. Mix sour cream, lemon peel and maple syrup.
Place one tablespoon of cream in the middle of each cold dish. Cut the peach half into 4 compartments and place them in the middle of the sour cream. Cut lemon balm into strips and sprinkle over them.