For the Spinach Stuffing: Heat a large sauté pan or wok, drop in 1 knob of butter and when it starts to sizzle, tip in the spinach. Stir fry, letting it wilt in the heat of the pan for about 45 seconds, so its still bright green. Remove and drain in a colander or sieve, pressing with the back of a spoon to extract all the liquid. Tip onto kitchen paper and pat dry.
Melt the remaining knob of butter in the same pan, then stir in the shallots. Fry for a few minutes until they have softened and are tinged brown. Stir in the raisins, then return the dried spinach to the pan. Mix together then transfer to a bowl, season with sea salt and pepper and leave to cool.
For the Potatoes: Scatter the sliced potatoes and garlic slices in a large roasting tin, then drizzle over the olive oil and gently toss together. Season with salt and pepper, then spread out in an even layer in the tin. Roast for 15 minutes.
For the Salmon: Lay one half of the salmon fillet on a chopping board. Slip 2 pieces of string underneath, one going under each end so you can tie the fillets together later. Brush or rub a little olive oil over the salmon, season it, then scatter over a few small dill sprigs. Spread the stuffing over the top, then lay the other half fillet over it, so the tail ends are both together. Brush or drizzle the top with a little more olive oil, then sprinkle over some sea salt and pepper. Bring the string over and use to tie the 2 fillets together.
Remove the potatoes after they have been roasting for 15 minutes, then raise the oven to 230C/fan 210C/gas 8. Lay the stuffed salmon on top of the potatoes and roast together for 15-20 or until the salmon is just cooked and the potatoes crisp and golden. If the salmon is done before the potatoes, remove and let it sit on a board for 5 minutes, covered with foil, while the potatoes finish roasting.
Pour any liquid that has leached out of the turbot into the sauce. Serve with the turbot, buttered spinach and mashed potato.
When almost ready to serve, mix together the soured cream and snipped dill, then season with some pepper. Heat 1 tablespoon of olive oil in a frying pan, tip in the spring onions and stir fry them on a high heat for about 2 minutes, until just starting to turn brown on the edges. Lift off the salmon and lay the onions on top of the potatoes, or transfer everything to a heated serving plate. Sit the salmon on top and serve scattered with more small sprigs of dill and the soured cream and dill dip.
Recipe Courtesy of Angela Nilsen: