How to Make It
Put the rice in a large bowl and cover with 2 inches of water. Let stand overnight.
Drain the rice. Line a large, wide steamer with a damp kitchen towel. Spread the rice on the towel in an even layer. Bring 1 inch of water to a boil in the bottom of the steamer. Add the rice, cover and steam over moderate heat for about 40 minutes, until tender and translucent. Fluff the rice.
Meanwhile, put the dried shiitake in a medium bowl and cover with the boiling water. Let soak until softened, about 20 minutes. Cut off the stems and cut the caps into 1/2-inch pieces. Carefully pour the soaking liquid into a cup, stopping before you reach the grit at the bottom.
Preheat the oven to 375°. In a large, deep skillet, heat 3 tablespoons of the vegetable oil. Add the shallots and cook over moderate heat, stirring, until translucent, about 3 minutes. Add the fresh shiitake, cover and cook, stirring a few times, until softened, about 5 minutes. Add the reconstituted shiitake, season with salt and pepper, cover and cook for 2 minutes. Scrape the mushrooms into a medium bowl.
Add the remaining 3 tablespoons of oil to the skillet. When the oil is hot, add the scallions and sausage and cook over moderately high heat, stirring, until the sausage is heated through, about 2 minutes. Add the water chestnuts and cooked chestnuts and stir to heat through, about 1 minute; season with salt and pepper. Add the mushrooms, 1 cup of the shiitake soaking liquid, the Shaoxing, soy sauce and sugar and bring to a boil. Add the steamed rice and stir to incorporate all of the ingredients. Stir in the chopped cilantro and season with salt and pepper.
Oil a large, shallow baking dish. Pack the rice into the dish and cover with foil. Put the dish in a large roasting pan. Pour enough water onto the pan to reach halfway up the side of the dish. Cover the pan with foil and bake for 1 hour, until the rice is heated through. Garnish with the cilantro sprigs and serve.