Baby Bok Choy with Sherry Vinaigrette

Trim bok choy and separate stems. Rinse under cold water and dry well. Cut the stems into roughly 2-inch pieces (you should have about 4 cups). Keep the leaves whole. Combine vinegar, sesame oil and mustard in a small bowl; set aside.

Heat a 14-inch flat-bottomed wok or large heavy skillet (not nonstick) over high heat until a bead of water vaporizes within 1 to 2 seconds of contact. Swirl in peanut oil, add garlic and stir-fry until fragrant, about 10 seconds. Add the bok choy stems and stir-fry for 1 minute. Add the leaves and sprinkle with salt and pepper; stir-fry until the leaves are just limp and bright green, about 30 seconds. Swirl in sherry and stir-fry until the stems are just crisp-tender, 30 seconds to 1 minute. Transfer to a serving bowl. Add the reserved vinegar mixture and toss to combine.