Begin by slicing the boneless beef shank into 4 to 5-inch pieces for even cooking. Bring a pot of water to a rolling boil, then add the beef and blanch for 30 seconds. Drain and rinse under cold water.

In a heavy-bottomed pot, combine the beef with ginger, garlic, scallions, and spices, including rock sugar, Shaoxing wine, and soy sauces. Add enough water to cover the beef. Bring to a boil and then simmer gently for 1 hour, until fork-tender.

After braising, remove the beef and let it cool for about 15 minutes. Chill in the refrigerator for a minimum of 2 hours.

While the beef cools, prepare the scallion pancakes. Heat a skillet and pan-fry the pancakes until golden and crisp, about 2-3 minutes on each side.

Once chilled, slice the beef thinly against the grain. Take a scallion pancake, spread hoisin sauce on it, layer with sliced beef, scallions, cilantro, and cucumber. Roll tightly.

Slice each rolled pancake in half, arrange on a platter and serve immediately. Enjoy with extra hoisin sauce for dipping.