Wash the tomatoes, dab dry and cut into thick slices. Clean and wash spring onions and cut into rings. Wash thyme and shake dry. Wash lemon hot, rub dry and cut into slices.
Wash the pike-perch fillet, dab dry and cut into 8 pieces. Season fish fillet and tomato slices with salt and pepper. Lay 4 times 2 sheets of parchment paper (approx. 50 cm long) on top of each other and place 3 slices of tomatoes and 2 pieces of fish with 1-2 slices of lemon and a stalk of thyme in the middle of each.
Sprinkle with 1/4 of the spring onions and place 10 g of herb butter on each. Fold parchment paper into closed packages and place on a baking tray. Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for about 20 minutes.
It goes well with rice.