Asian Duck Wraps with Hoisin Dipping Sauce

Duck breasts vary in size. Buy by weight, and you will get the right amount. If they turn out to be quite large, slightly increase the baking time. Mu shu pancakes are basically very thin pancakes made with flour, water, and sesame oil.
In a large bowl, combine 2 tablespoons of soy sauce and rice vinegar, ginger, garlic, sesame oil,and five Chinese spices. Add the duck breasts, flip to coat well, cover and refrigerate for 2 hours. Remove the breasts from the marinade (discard the marinade) and place skin side up on a baking sheet; refrigerate, uncovered, overnight.In a small bowl, combine the hoisin, sugar, mustard, and remaining 2 tablespoons of each soy sauce and rice vinegar. Pour ice water into another bowl and add the green onions.Preheat the oven to 425 degrees. Preheat a large nonstick skillet over medium-high heat. When hot, add the vegetable oil, then duck breasts, skin side down. Cook until the skin is lightly browned and crisp, about 5 minutes. Carefully tilt the pan and use a spoon to remove any excess duck fat. Turn the breasts upside down and place the pan in the oven.Bake until the duck is slightly pink in the center of the thickest part (cut one for the dough), about 8 minutes. Let stand for about 5 minutes. Drain the green onions.Transfer the duck breasts to a board and cut into thin slices. Carefully divide the pancakes and place each one flat. Fold each circle in half and add a few slices of duck. Drizzle the duck with a small amount of sauce, and sprinkle with green onion slices on top. Turn the duck with one side of the pancake, then roll it into a bundle. Serve with the remaining dipping sauce.* In Asian markets and well-stocked supermarkets, you can find mu shu pancakes (sometimes called "mok shu").