Heat the oven to 200°C/Gas 6. Bring a pan of water to the boil, add the potatoes, and cook them for 8 minutes. Place them in a colander to drain and let them steam dry for a couple of minutes.
On a baking tray, toss the potatoes in roughly half of the oil and season with salt and pepper. Place in the oven and cook for 20 – 25 minutes, tossing them every now and then.
Add the leek, the chives and the garlic to the remaining oil in a frying pan over a medium heat and fry for 5 minutes.
Add the cream and 150 ml of hot water.
Heat the grill. Pour the creamy leek mixture over the potatoes.
Season the salmon fillets with salt and pepper and place them on top of the potatoes.
Grill for 10 minutes, until the salmon is cooked through.
