Let the fish thaw for 20-30 minutes. Rinse fish afterwards and dab dry. Sprinkle with lemon juice, season with salt and pepper. Peel onions and cut into rings. Divide cheese into 4 pieces. Place the fish, cheese and onion rings in portions on parchment paper and pack them into a parcel, but do not close it. Cook in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 10 minutes.
In the meantime, bring the vegetables to the boil in 200 ml lightly salted water with 1 pinch of sugar. Let them simmer for 10 minutes at low heat. Stir in the rice 3 minutes before the end of the cooking time, season to taste again. Wash herbs, shake dry and chop except for a little bit for garnishing. Arrange fish and vegetable rice on plates. Sprinkle with herbs and garnish
30 minutes waiting time