1 In a small measuring cup mix soy sauce, vinegar, sugar, sesame oil, and cornstarch until smooth. Pour half into a medium bowl for marinade and reserve the other half until later. 2 Slice the beef across the grain into very thin narrow slices; stir beef into marinade mixture and marinate at least 20 minutes. Meanwhile cook rice according to package directions.3 Separate stalks of bok choy and remove leaves set both aside.4 In a large non-stick skillet or wok heat 2 tsp oil until hot over medium- high heat; add ginger, garlic and pepper flakes and stir-fry 30 seconds or until fragrant but not browned.5 Remove beef from marinade with slotted spoon: add to hot skillet and stir-fry 2-3 minutes or until browned. Transfer all to a bowl.6 Add remaining 1 tsp oil to the skillet. Add bok choy stalks, carrots, onions and mushrooms; stir-fry 3-5 minutes; add broth and corn; cover and steam 2-3 minutes or until vegetables are crisp- tender. 7 Stir in bok choy leaves and push vegetables to the side of skillet; pour reserved starch mixture and left over marinade into middle of skillet; bring to boil for 1 minute, stirring constantly until slightly thickened. 8 Return the meat mixture with any accumulated juices and peanuts; toss just until hot. Serve over hot rice and garnish with cilantro or green onions.
Source: Photo and Recipe Courtesy of Mushroom Council and Mushroominfo.com