Peel and slice the onion. Wash the fish with cold water and then dab dry with kitchen paper. Sprinkle fish fillets with salt and pepper on one side. Spread with pesto, roll up and stick together with wooden skewers. Bring 750 ml water, lemon juice, salt, peppercorns, onion and bay leaf to the boil in a small pan. Carefully add the fish rolls and let them simmer at low heat for about 8 minutes. After half the cooking time, carefully turn the fish rolls.
In the meantime, put deep-frozen cream carrots in a small saucepan with 150 ml water, bring to the boil in an open saucepan over a high heat. Then simmer for 5-6 minutes at low heat, stirring several times. In the meantime wash parsley, dab dry and chop finely. Remove the fish rolls from the stock, let them drain briefly and serve on top of the creamed carrots. Sprinkle with parsley and garnish as you like with dill flags and lemon wedges. Serve with fresh baguette bread