1 small head of spring greens, stem removed, roughly shredded
25g toasted walnuts, chopped
Pour 2 tbsp water into a sauté pan on a medium heat and stir in the butter and walnut oil. Bring the mixture to the boil, add the spring greens, stir gently, then turn the heat off and put a lid on the pan.
Just before the fish comes out of the oven, turn the greens back on to finish wilting them, then scoop into a serving dish and scatter with the chopped walnuts.