- 12 dried shiitake mushrooms
- 1 3-inch-long piece fresh ginger, peeled, thickly sliced
- 3/4 cup coarsely chopped fresh cilantro
- 4 1/2 tablespoons black bean garlic sauce
- 1 1/2 teaspoons Chinese five-spice powder
- 6 large lamb shanks (about 1 pound each), excess fat trimmed
- 3/4 cup thinly sliced green onions
Place mushrooms in bowl. Pour boiling water over; let soak until mushrooms soften, at least 45 minutes and up to 4 hours. Strain mixture, reserving 1 1/2 cups soaking liquid. Cut stems from mushrooms and discard; thinly slice caps.
With food processor running, add ginger and garlic and finely chop. Add cilantro, black bean sauce, 2 teaspoons peanut oil, and five-spice powder. Process until paste forms, occasionally scraping down sides of work bowl. Using sharp knife, cut 5 small shallow slits into each lamb shank, spacing apart; rub generous 1 tablespoon black bean-cilantro paste into slits and all over surface of each shank. DO AHEAD Mushrooms and lamb shanks can be prepared 6 hours ahead. Cover mushrooms, soaking liquid and shanks separately and chill.
Preheat oven to 325°F. Cut six 18-inch squares of aluminum foil; place on work surface. Place green onions and sliced mushroom caps in center of each foil square, dividing equally. Heat remaining 4 teaspoons peanut oil in heavy large skillet over medium-high heat. Working in batches, add lamb shanks and cook until brown on all sides, about 5 minutes per batch. Place 1 lamb shank atop green onions and mushrooms on each foil square.
Pour reserved mushroom soaking liquid and Sherry into same skillet. Boil until liquid is reduced to 3/4 cup, scraping up any browned bits from bottom of skillet, about 10 minutes. Spoon 2 tablespoons reduced liquid over each lamb shank, pulling up foil around shanks to prevent liquid from spilling out. Enclose shanks completely in foil, twisting foil to seal; place on large rimmed baking sheet.
Bake lamb shanks until very tender and meat almost falls off bones, about 2 hours. Open up foil packets; place each atop bowl of steamed rice, allowing diners to remove foil.