• First wash, halve and quarter the sweet potatoes. Mix the olive oil, crushed garlic, a little sea salt and pepper, add the chopped rosemary and sweet potatoes and marinate for approx. 30 minutes. Then cook at 180°C for about 30 to 40 minutes on the top rung of a BBQ (indirect heat) or in the oven.
• Meanwhile, cut the salmon fillets into cubes of about three centimetres, cut the vegetables into similar sized pieces. Except for the cherry tomatoes, which remain whole.
• Thread the salmon and vegetables alternately onto the skewers. It is best to use two long skewers for each person.
• To prepare the ginger lemon sauce, peel the ginger and chop finely. Then squeeze the lemon.
• Heat the butter and sauté the ginger in it, then add the plain flour and cook for one minute whilst stirring constantly. Pour in the fish stock, still stirring constantly to ensure no lumps appear. Once the sauce is smooth and glossy, stir in the single cream and lemon juice and season to taste with sea salt and nutmeg.
• Grill the salmon skewers with vegetables on both sides. This is best done over a medium direct heat for about 3 to 5 minutes each, either directly on the BBQ  (brush the skewers with a little olive oil before putting on the BBQ) or on a griddle plate or in a pan. (Put olive oil on the griddle plate or in the pan and heat before adding the skewers).
• Sprinkle the skewers with sea salt and pepper and serve with the ginger-lemon sauce and sweet potatoes.

Tip:

Salmon and vegetables, especially courgettes, have different cooking times. So if you put thick pieces of courgette on your barbecue skewer, your salmon will be cooked through before the courgettes are. It's better to put thinly sliced courgettes on the skewer.