Use the baking tray that comes with the oven.

Spread half the vegetables into layers. The onions first, then the tomatoes and the garlic, parsley, salt, pepper and oregano on top.

Then spread the pangasius fillets and repeat the previous vegetable layers, adding the potatoes as well.

Pour the oil over everything and place the baking tray on the bottom rack of the oven, at 170°C for about an hour.