Wash the potatoes, bring to the boil covered with water and cook for about 20 minutes. Mix the egg yolks, 1/2 teaspoon salt, mustard, sugar and lemon juice with the whisks of the hand mixer on the highest setting for about 2 minutes. Stir in the oil in a thin stream. Finely chop the capers and anchovy fillets. Cut cucumbers into fine cubes. Wash parsley and chop finely. Add capers, anchovy fillet, cucumber and parsley to the mayonnaise.
Season with salt, sugar and pepper. Drain potatoes, rinse and peel. Heat oil in a frying pan. Fry the potatoes for about 8 minutes. Season with salt and pepper. Arrange potatoes, sausage and tartar sauce on plates