Wash the potatoes and cook in boiling water for about 20 minutes. Clean, wash and cut the peppers into very fine cubes. Stir quark smooth and season with salt, pepper, sugar and lemon juice.
Cut cress from the bed. Stir in half of the cress and the paprika cubes. Drain the potatoes, rinse and peel. Arrange potatoes with ham and curd on a plate. Sprinkle with the remaining paprika and cress.