Delicate white miso (a pasted made from fermented soybeans) mixed with a nugget of pungent blue cheese makes a rich sauce for these juicy lamb racks. Don't substitute one of the more strongly flavored darker misos. Have your butcher french the lamb racks—that is, scrape the fat and gristle from the bones. More Amazing Lamb Recipes
How to Make It
Preheat the oven to 450°. In a medium saucepan, bring the chicken stock to a simmer over moderate heat. Stir in the miso until dissolved. Add the blue cheese and stir until dissolved. Add the soy sauce and mirin and simmer for 1 minute, stirring constantly. Strain the sauce into a clean saucepan.
Season the lamb racks with salt and white pepper. In a large ovenproof skillet, heat 2 tablespoons of the oil until almost smoking. Set the lamb racks in the skillet, fat side down, and sear over high heat until nicely browned, about 5 minutes. Turn the racks over and brown the bottoms, about 3 minutes. Transfer the skillet to the oven and roast the lamb for about 25 minutes for medium rare, or until an instant-read thermometer inserted in the thickest part of the meat registers 125° to 130°. Transfer the racks to a cutting board, cover loosely with foil and let rest for 10 minutes.
Meanwhile, in a medium skillet, heat the remaining 1 tablespoon of oil. Add the red pepper and cook over moderately high heat until barely tender, about 2 minutes. Add the arugula and stir until just wilted. Season with salt and white pepper.
Reheat the sauce and season with salt and white pepper. Transfer the arugula mixture to 4 large plates. Carve the racks into individual chops and arrange 4 on each plate. Spoon about 1/4 cup of the miso-blue cheese sauce over and around the meat. Sprinkle with the chives and black sesame seeds and serve at once.