1. Rinse meat reduce 3- to 4-inch lengths (for chuck, about one in. thick and 1 1/2 in. wide) and put inside a 5- to six-quart slow-oven.
2. Having a vegetable peeler, pare orange a part of peel from orange and sliver it save orange for other uses. Inside a 1 1/2- to two-quart pan, combine peel, onion, 1 cup broth, wine, port, vinegar, soy sauce, thyme, ginger root, and five spice. Provide a boil over high temperature. Pour liquid over meat. Turn slow-oven to high, cover, and prepare until meat is extremely tender when pierced, five to six hrs.
3. Rinse and drain mushrooms trim off and discard stem ends. Cut mushrooms in two lengthwise and put inside a 10- to 12-inch fry pan add butter.
4. Skim off and discard fat from liquid in slow-oven. Ladle 1 cup liquid into pan with mushrooms. Stir mushrooms frequently over high temperature until liquid has evaporated and mushrooms are gently browned, 13 to 17 minutes.
5. Having a slotted spoon, lift meat from juices in slow-oven and lay in one layer inside a shallow casserole (about 9 by 13 in.). Pour mushrooms over meat. Bake inside a 375° regular or convection microwave until meat is sizzling and browned, 12 to fifteen minutes.
6. Meanwhile, measure remaining liquid from slow-oven. If under 2 cups, add beef broth to create 2 cups, pour right into a 2- to three-quart pan, and produce to some boil over high temperature if there's more, pour into pan and boil, stirring from time to time, until reduced to two cups, eight to twelve minutes. In a tiny bowl, mix corn starch with 1/4 cup water. Pour into boiling liquid and stir until thickened, about thirty seconds. Pour evenly over meat and blend lightly to combine with liquid in casserole, adding pepper and salt to taste. Sprinkle with chives.