Ten minutes in, pre-heat the oven to 180ÃÂºC. Now, you'll be making the fish parcel. Take enough tin foil to wrap up the fish. Place the foil on a baking paper, then drizzle 1/2 tbsp soy sauce on top of it. Place the trout over the soy sauce, and sprinkle with some salt and pepper. Chuck in the second slice of lemon, and cook it for about 25 minutes.