Preheat the oven to 190°C, gas mark 5. Cook the potatoes in boiling water for 4-5 minutes, until just tender but not breaking up. Drain and refresh under cold water.
Place the spinach in a colander and pour over a kettle of boiling water until the spinach has wilted. Leave it to cool then squeeze out the excess water.
Brush a little melted butter or olive oil over the base of a 20cm x 30cm ovenproof dish, then layer with half of the potatoes. Now spread over half the spinach and half the salmon, spreading it out evenly.
Add another layer of potatoes, the rest of the spinach and salmon, then finish with a final topping of potato.
Mix together the cream and wine, then pour over the top. Season well then arrange the cheese evenly all over.
Bake for 45-50 minutes until the topping is crisp and golden. Serve with steamed sugar snap peas and a sprinkle of fresh dill