Lamb Fillet with Watercress Salad and Buttermilk Dressing
Rinse the lamb, pat dry, and season with salt and pepper to taste. Heat 1 tablespoon of the oil in a skillet and sear until golden on all sides. Cover the pan with foil and allow the lamb to rest until medium rare.
Peel and finely chop the shallot and garlic. Heat the remaining oil in a saucepan. Stir in the shallots and garlic, and sweat until translucent. Stir in the broth and buttermilk, and allow to warm slightly. Season with salt and pepper to taste. Use a hand blender to froth the sauce. Blanch the broad beans in a pot of boiling salted water until tender, about 6 minutes.
Rinse the watercress and spin dry. Drain the beans. Divide the watercress and beans between individual serving plates. Pat the lamb fillet dry and slice. Top each salad with some of the lamb and drizzle with the buttermilk foam.