CHICKEN HEART YAKITORI

Steps:

• To make the sauce: Heat oven to 400 degrees. Spread the bones in a saute pan and roast until the bones are brown and the fond at the bottom of the pan is beginning to darken, about one hour.
• Remove the pan from the oven and put on a stovetop. Deglaze the pan with about 1/3 of the sake, scraping up the browned bits until the bottom of the pan is clean. Then add in the rest of the sake, mirin, sugar, and soy sauce. Bring to a boil, then simmer until the sauce is thickened, about one hour. Season with black pepper. Leftover sauce will keep in the refrigerator indefinitely if reheated once a week.
• To grill: skewer chicken hearts and set over a medium high flame.
• When the chicken hearts are almost cooked through, about 2 minutes, baste with the sauce and grill again until sauce is dried, about 20 seconds.
• Baste again and grill just until the sauce is starting to dry, about 10 seconds.
• Sprinkle with sansho pepper if desired. Serve with wedges of lemon, salt, and mustard on the side.