Peel onion and cut into rings. Clean, wash and halve the mushrooms. Tomatoes wash, halve. Cut mozzarella into slices. Roughly pluck tuna
Separate the toasties and place them on a baking tray lined with baking paper. Spread the sauce on top. Cover 4 toasties with tuna and onion. Cover 4 more with mushrooms, salami and gouda and the rest with mozzarella and tomatoes. Season all with salt and pepper
Bake in the preheated oven (electric cooker: 200 °C/circulating air: 175 °C/gas: level 3) for approx. 15 minutes. Wash the herbs, chop if necessary and garnish the pizzas with them
Drink: cool mineral water or red country wine