Heat the oven to 200°C/180°C fan/gas 5.

Bring a large pan of salted water to a boil, then add the potatoes and cook until just tender.

Drain, then transfer to a baking tray and allow to cool slightly.

Drizzle with a little oil, then roast in the oven for 15 minutes.

Whilst the potatoes are cooking, in a saucepan, gently melt 50g of the butter.

Add the chopped sage, garlic and cook in the butter for 1-2 minutes until the sage starts to go crisp.

When the potatoes have been in the oven for 15 minutes, pour over the sage butter making sure the potatoes are coated well.  Continue to roast. until the potatoes are golden and crisp.

Season the fish fillets and heat the olive oil, over a medium heat,  in a frying pan.

Fry the fish, skin-side down, for about 3 minutes.  Flip and cook the fish on the other side for 2 minutes.

Take the fish off the heat.

To serve, melt the remaining butter in a frying pan and fry the whole sage leaves until crisp.  Serve the fish with the potatoes, topped with the sage leaves, and any leftover melted butter from the frying pan.