Preheat a frying pan with a thick bottom, 15 g butter, add leeks coarsely chopped (only the white and light green parts), chopped into cubes and carrots. saute 5 minutes. Clean the trout, sprinkle with salt, pepper and half the thyme inside and out, inside each put 5-7 grams of butter. Place the big fish in a baking dish, cover with a mixture of leeks and carrots, add the pieces of bay leaf, cover with Riesling. Bake at 220 C for about 15 minutes.
The hot fish and vegetables to put in a dish, cover with foil. Pour the juices from the pan into a saucepan, boil for 3 minutes, add the remaining oil and thyme, season with salt and pepper and pour over the sauce and serve fish.