Peel and wash the potatoes. Clean the turnips, leaving a little green on the turnips. Halve the turnips. Coarsely crush the pepper in a mortar. Heat milk and pepper in a large pot, except for some garnish. Season with salt. Cook the turnips and potatoes in the milk for about 20 minutes over a low heat, stirring occasionally.
In the meantime, wash the fish, dab dry and cut into 4 equal pieces. Heat the oil in a pan. Fry the fish in it from the skin side at medium heat for about 3 minutes until golden brown. Turn, add butter and fry for another 2 minutes at low heat. Season with salt
Wash the dill, shake dry and chop coarsely. Drain 250 ml of milk from the potatoes and foam up. Arrange milk, potatoes, turnips and fish in bowls. Add milk foam and sprinkle with plenty of chopped dill