Cut the meat lengthwise into 3 strips. Cut the strips crosswise into ¼-inch-thick slices. Place them in a bowl. Add the marinade and mix until well blended. Let the meat marinate in the refrigerator for 30 minutes or longer.
Wash the asparagus well; snap off the tough ends, then roll-cut the stalks into 1½-inch pieces, leaving the tips intact. Place them on your working platter with the ginger and garlic. Combine the sauce seasonings, and have the other ingredients and a strainer within reach.
Heat a wok or large, heavy skillet over high heat until very hot; add the 2cups oil and heat until hot, about 375 degrees. Scatter in the beef, swish, and toss for about 10 seconds, until the meat is superficially whitened. Hold the strainer over the pan and spoon the meat rapidly into it, drain for a moment, then turn it onto a plate. These preparations may be done up to an hour in advance, but don’t refrigerate the meat. When oil is cool, rebottle it for general cooking.
Set wok or skillet over high heat, add 2tablespoons oil, and heat about 30 seconds. Toss in the ginger and garlic and press them rapidly in the oil. Scatter in the asparagus and toss it briskly for about 1 minute, until the color brightens. Sprinkle in the salt and sugar and stir well; dash in the sherry and stir a few more times. Pour in the stock or water, even out the contents, cover, and steam-cook vigorously for 1 minute. Uncover, add the beef, and toss the two in fast turning and flipping motions a few times. Add the sauce and stir contents in rapid sweeping motions until the sauce is thickened and smoothly glazed onto the meat and vegetables. Pour into a hot serving dish.