Spray a medium sized baking dish or oven proof pan e.g. cast iron with olive oil to prevent sticking. Place the fish into the dish/pan skin-side down (if the fish has skin).

Preheat the oven to 410F/210C. Then put the potatoes into a large pot of salted water and bring to the boil. Boil for 2 minutes, drain and let steam. Alternatively, boil for 10 minutes in water that's already boiling.

Empty the drained potatoes onto a large baking sheet lined with baking paper. Drizzle with olive oil and toss with your hands. Bake in one layer for around 30 minutes or until cooked through, golden, and a little crispy.

Meanwhile, combine the panko crumbs, lemon zest, basil, parmesan/other cheese, garlic powder and paprika (if using), salt and pepper in a small bowl.

Pile half of the panko mixture onto the top of each of the fish fillets in the baking dish/pan. Bake for 10 to 15 minutes - just until the flesh has turned completely white. The inside of the fish should be at least 145F/63C (check with a meat thermometer if you like).

Quickly melt the butter around the fish while it's still in the pan. Then add the lemon juice and swirl a little with a spatula or wooden spoon to combine.

Serve the crispy cod and sauce immediately with the cooked chips/fries and a side of frozen peas (if you like). Scatter a little more fresh basil over the top if you like.