Use the freshest salmon you can find – left raw, it will very lightly cook in the residual heat of the hot soup.
45g/2oz unsalted butter
1 onion, chopped
1 small potato, peeled and cut into small cubes
1 tsp vitamin C powder
340g/12oz fresh sorrel, leaves only, chopped
1 small round lettuce, leaves separated, chopped
20g/1oz fresh chervil, chopped
900ml/1½ pints vegetable stock (see above)
4-6 tbsp double cream
For the vegetable stock, place all of the vegetables and herbs into a deep, heavy-based pan and cover with the water. Season with salt and freshly ground black pepper and bring to the boil. Reduce the heat and simmer for 30 minutes, then strain, discarding the solids. Measure out 900ml/1½pints for the sorrel soup.
Preheat the oven to 160C/325F/Gas 3.
For the oatcakes, mix together the oatmeal and bicarbonate of soda in a bowl, then quickly mix in the melted lard and water until the mixture comes together to form a rough dough.
Turn the dough out onto a floured work surface and roll out to a thickness of 5mm/¼in. Cut out rounds using a pastry cutter, then transfer to a non-stick baking sheet and bake for 25 minutes, or until golden-brown and crisp. Remove from the oven and set aside to cool.
For the sorrel soup, melt the butter in a pan until foaming, then add the onion and potato and fry for 4-5 minutes, or until softened but not coloured.
Add the vitamin C powder, sorrel, lettuce and chervil and cook for 1-2 minutes, or until the vegetables are wilted. Add the vegetable stock, then remove from the heat and blend to a smooth purée using a stick blender. Return to the heat, then stir in the cream and season to taste with salt and freshly ground black pepper.
Mix the cubed salmon and dill together in a bowl, then divide among four soup bowls, arranging the salmon in a small pile in the centre.
To serve, pour the soup around the salmon. Serve the oatcakes alongside.
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