Place a heavy-based saucepan over a medium heat and add the butter. Once the butter has melted, add the potatoes and onion, stir well and cover the pan with a lid. Reduce the heat to low and leave the vegetables to sweat for about 10 minutes, stirring occasionally.
Pour in the hot stock, increase the heat to high and cook, uncovered, for about 10 minutes until the potatoes and onion are completely soft.
Using gloves, add the nettles (they lose their sting once cooked) and nutmeg,
stir and cook for 2–3 minutes until the nettles have wilted. Transfer the soup to a blender or food-processor, or use a hand blender, and blend to a smooth consistency. Return the soup to the saucepan (if necessary) and season. Stir in the cream and place over a medium heat for just 2 minutes to warm through.
Meanwhile, make the scones. Preheat the oven to 200°C/Fan°C 180/Gas 6. Spread the dulse out on a baking tray and roast in the oven for 2 minutes, then remove from the oven.
Sift the flour, baking powder and salt into a large bowl. Add the butter and rub
in with your fingertips until the mixture resembles fine breadcrumbs. Stir the dulse into the mixture, then gradually mix in enough buttermilk with a fork to make a soft dough. Roll out the dough on a floured work surface to a thickness of 1cm. Cut into rounds using a 7.5cm pastry cutter or an upturned glass.
Oil the baking tray used for the dulse, place the rounds on the tray and brush with buttermilk. Bake for 12–15 minutes until golden brown. Transfer the scones to a wire rack and leave to cool for 10 minutes before serving. Serve the soup in warmed bowls, garnished with clover blossoms, along with the warm seaweed scones.