For the vegetable fish gratin, boil peas with the peel until soft. Marinate fish fillets with lemon juice.
Cut eggplant and bell bell pepper into small cubes. Marinate with chopped herbs, pressed garlic and olive oil.
Preheat the stove to 180 degrees convection. Peel cooked potatoes, cut into slices and line the bottom of a baking dish with them.
Season lightly with salt and pepper. Place the fish fillets on top of the potatoes and also season with salt and pepper. Spread the vegetable mixture on top of the fish, salt and pepper again.
Finally, place the sliced mozzarella on top of the vegetables. Close the baking dish and cook in the oven for 30 minutes.
Then gratinate for another 5 minutes without the lid. Sprinkle the vegetable-fish gratin with freshly chopped parsley before serving.