Clean and wash the tomato and remove the stalk. Blanch in boiling water for about 1 minute. Remove with a skimmer and cool in ice water. Peel the tomato skin. Cut tomato crosswise in half, remove seeds and dice flesh.
Clean and wash the spinach and let it drain on a sieve. Peel the shallot and cut into fine cubes. Cook rice in boiling salted water according to package instructions. Wash the fish and cut in half lengthwise.
Boil 300 ml of water and wine. Season with laurel, salt and pepper. Cook the fish in it for about 5 minutes. Melt fat in a pot, stir in flour and sweat for about 1 minute. Measure out 100 ml fish stock and stir it quickly into the roux with yoghurt.
Bring to the boil. Season to taste with salt, pepper and lemon juice. Meanwhile, bring the stock and diced shallots to the boil in a flat pot. Add spinach and diced tomatoes. Steam in closed pot for about 4 minutes.
Season to taste with salt, pepper and nutmeg. Arrange vegetables, fish, rice and sauce on a plate. Sprinkle with coloured pepper.