To begin, make the walnut purée. Drain the walnuts (reserving a little pickling liquid) and place in a food processor. Blend on high, slowly adding some of the pickling liquid to form a thick, smooth purée. Pass through a fine sieve and transfer to a clean bowl
To prepare the salad leaves, cut the base from the chicory and remove any damaged leaves. Separate the leaves and trim the ends
Trim the outside of the fris?©e lettuce and pick some nice pieces from the heart
To cook the steaks, season with salt and pepper, pressing firmly into each side
Place a pan over a medium heat, add the oil and butter and cook until the butter is foaming and smells nutty, but is not burnt
Increase the heat and lay the steaks in the foaming butter. Cook for 2 minutes on each side, then remove from the pan and leave to rest in a warm place
To serve, add the chicory, fris?©e, blue cheese, chives and pickled walnuts to a bowl. Season with salt and black pepper and dress with a little walnut oil
Add a spoonful of the picked walnut purée to each plate and place a steak on top. Dress with the salad and serve.