Peel the onions, cut one into slices and dice one finely. Peel, wash and thinly slice carrots
Wash the fish and pat dry. Season with salt and pepper and spread with pesto. Roll up the fish and pin it. Boil up approx. 1/8 l water, lemon juice, salt, peppercorns, bay leaf and the onion wedges in a wide pot. Steam the fish rolls in the stock at low heat for about 8 minutes
Heat the fat. Sauté the onion cubes in it. Add the carrots and steam briefly. Deglaze with 6 tablespoons of water, cover and steam for about 7 minutes. Add cream, bring to the boil and simmer for about 5 minutes
Wash and chop the parsley. Stir into the vegetables and season to taste. Drain the fish rolls. Arrange on the vegetables, garnish if necessary. Goes well with fresh white bread