Heat the oven to 220C/fan 200C/gas 7. Cut the potatoes in half lengthways, then cut each half into 3 or 4 wedges, depending on their size.  Put them in a bowl and toss with olive oil, dried oregano or thyme and some salt to coat the wedges. Spread them out in a single layer, cut-side down, on a large baking tray or shallow roasting tin. Bake for 18 to 20 minutes, turning the wedges after 10 minutes, until crisp and golden all over.

Meanwhile, mix together all the parmesan crust ingredients and set aside. Boil a kettleful of water.

Tuck any thin ends of the fish fillets underneath so they are an even thickness. Spread the parmesan crust mixture evenly over the top of the fish, patting gently to ensure the fish is well coated, then nestle the fillets between the wedges on the tray, moving the wedges to make space if needed, but keeping everything in one layer. Bake at the top of the oven for 5 to 7 minutes, depending on the thickness of the filletts, until the fish is just cooked through.

Meanwhile, put the samphire into a heatproof bowl and pour over enough just-boiled water from the kettle to cover it. Leave for 5 minutes, then drain and stir in the butter (if using). Add the samphire to the baking tray or roasting tin when the fish is cooked, then serve, with tartare sauce if you like...and enjoy!