This Cantonese dish, with its mouth-watering combination of pungent, savory, sweet and sour tastes, comes from the area along the Eastern River in Kwangtung province.

Ingredients:

8 ounces (225 grams) canned pickled mustard green, rinsed
2 1⁄4 tablespoons sugar
12 ounces (350 grams) beef, skirt, steak, rump or fillet
1 teaspoon potato flour
6 tablespoons water
5 tablespoons peanut or corn oil
4 or 5 cloves garlic, peeled and chopped fine
4 scallions, cut into 1-inch (2.5-centimeter) sections, white and green parts separated
1 tablespoon Shaohsing wine or medium-dry sherry
1⁄4 to 1⁄2 inch (5 millimeters to 1 centimeter) fresh ginger root, peeled and chopped fine or sliced

For the marinade:
1⁄4 teaspoon salt
scant 1 tablespoon thick soy sauce
8 turns black pepper mill
2 teaspoons Shaohsing wine or medium-dry sherry
1 teaspoon potato flour
2 tablespoons water
1 teaspoon sesame oil

Directions:

Shred the pickled mustard green into narrow pieces. Put into a bowl, add the sugar and mix well. Let stand at room temperature for up to 1 hour.

Cut the beef across the grain into slices about 1 by 1 1⁄2 inches and 1 1⁄4 inch (2.5 by 3.5 centimeters and 3 centimeters) thick. Put into a bowl.

Prepare the marinade: Add the salt, soy sauce, pepper and wine or sherry to the beef. Sprinkle with the potato flour and add the water, 1 tablespoon at a time, stirring until it is difficult to continue before adding another spoonful. This process will make the beef velvety and tender. Put in the refrigerator for 30 minutes. Blend in the sesame oil.

Mix the 1 teaspoon of potato flour and the water in a small bowl and put aside.

Heat a wok over high heat until smoke rises. Add 4 tablespoons of the oil and swirl it around. Add the garlic, and as soon as it takes on color, add the white scallions and stir. Add the beef. Sliding the wok scoop or metal spatula to the bottom of the wok, turn and toss vigorously for 30 to 60 seconds, or until partially cooked. Splash in the wine or sherry around the side of the wok, continuing to turn and toss until the sizzling dies down. Transfer to a warm plate.

Add the remaining 1 tablespoon of oil to the wok and swirl it around. Tip in the ginger, stir, and then add the pickled mustard green. Stir and turn until piping hot and then push to the edge, leaving a well in the middle.

Return the beef to the middle and immediately pour in the well-stirred dissolved potato flour. Continue to toss the beef until this thickening has cooked. Stir in the green scallions. Transfer to a warm serving plate. Serve immediately.

Serves 4 with 2 other dishes.