Let the dough rest at room temperature. Peel, halve and slice the kohlrabi. Peel onion and garlic, dice finely. Bring 800 ml water and broth to the boil.
Heat 2 tablespoons of butter in a saucepan. Sauté onion and garlic in it. Steam rice and kohlrabi briefly. Add hot broth until the rice is covered. Cook until the rice has absorbed the liquid. Add the rest of the hot stock gradually, but only when the rice has absorbed the liquid. Cook for a total of 20-25 minutes.
In the meantime, line a baking tray with baking paper. Wash the herbs, shake dry, chop the leaves finely. Melt 3-4 tablespoons of butter. Preheat oven (electric cooker: 200 °C/circulating air: 180 °C/gas: see manufacturer). Spread out a damp cloth, place a dry one on top. Roll out dough sheets on top. Cut 4 sheets into 4 squares (rest of the dough can be used for other purposes). Brush each square with a little butter, place 2 on top of each other. Wash the fish, dab dry and cut into 8 pieces. Season with salt and pepper. Sprinkle with herbs. Place the salmon pieces in the middle of each square and wrap them in the dough, then brush with the rest of the butter. Put the packet on the baking tray and bake for about 15 minutes.
Clean and wash spring onions, cut into rings and stir into the risotto. Season with salt, pepper and lemon juice. Arrange everything.