Boil the potatoes for about 12 minutes until tender. Turn on the grill. Stir the curry paste into 4 tbsp of the lactose free yogurt and smear the mixture all over the salmon.
Put the salmon in a large heatproof dish, skin side up, and grill for 10 minutes.
Drain the potatoes and return to the pan. Add the remaining lactose free yogurt with the lactose free butter, chili flakes, coriander and lactose free milk.
Now mash the ingredients together, or better still use an electric hand whisk to beat the mash to a really creamy texture, adding extra lactose free milk if necessary.
Pile on plates, top with the salmon and drizzle with the cooking juices. Serve with grilled tomatoes.
