Wash and clean the beans. Clean and peel the carrots, halve them lengthwise and cut into slices. Cook rice in boiling salted water for 18-20 minutes. Rinse fish, dab dry. Sprinkle with juice of 1/2 lemon and season with salt and pepper.
Cook the beans and carrots in boiling salted water for about 8 minutes. Turn fish fillets in flour, tap. Heat oil in a coated pan. Fry pike-perch fillets for 2-3 minutes on each side. Bring milk and stock to the boil.
Stir in the sauce thickener, simmer for 1 minute while stirring. Season sauce to taste with juice of 1/2 lemon, lemon peel, salt, pepper and sugar. Drain rice and vegetables separately, drain.
Arrange fish fillets with rice, vegetables and sauce. Wash the dill, dab dry and chop finely, except for a few flags. Garnish with lemon wedges, dill flags and chopped dill.