Peel, wash and roughly dice the potatoes. Cover and cook in salted water for about 15 minutes
Peel the carrots, leaving a little green on the side. Wash the carrots, cover and steam in a little salt water for 10-15 minutes
Wash the fish, pat dry and cut into 3 pieces. Sprinkle with lemon juice, season. Wash herbs and chop finely
Heat the oil in a coated pan. Fry the fish for 2-3 minutes on each side. Drain potatoes except for 2-3 tablespoons of cooking water. Pour on half of the milk. Mash potatoes, season to taste and stir in herbs
Take out the fish. Deglaze the gravy with stock and the rest of the milk. Bring to the boil and thicken. Season to taste. Spray the puree in small tuffs onto the plate. Arrange and garnish everything