Sweet and Sour Spareribs

INGREDIENTS:

1½ lbs lean baby back pork spareribs, cut into single ribs
1 tsp salt
1 tsp unsalted butter
1 tsp cornstarch
1 tsp Shao Hsing rice wine or dry sherry
1 tsp lime zest, optional
½ tsp soy sauce
½ tsp olive oil
½ tsp sugar
½ tsp lime juice
1 tbsp olive oil
1/3 cup packed dark brown sugar
1/3 cup balsamic vinegar

INSTRUCTIONS:

In a large bowl combine ½ teaspoon of the salt, the sugar, cornstarch, rice wine, soy sauce, and the ½ teaspoon oil. Add the spareribs and combine. Marinate 1 hour. Pat dry completely with paper towels.
Heat a flat-bottomed wok over high heat until a bead of water vaporizes within 1 to 2 seconds of contact. Swirl in the remaining 1 tablespoon oil and add the spareribs meat side down, spreading them in the wok. Reduce the heat to medium and pan-fry undisturbed 5 minutes, letting the spareribs brown. Then, using a spatula, turn the spareribs over and pan-fry an additional 2 minutes.
Add the brown sugar, vinegar, and the remaining ½ teaspoon salt with 1/3 cup water to the wok and bring to a boil over medium-high heat. Turn the ribs meat side down. Cover, reduce the heat to low, and simmer 1 to 1½ hours, until the meat is tender. Add the butter and lime juice and stir to combine. Garnish with lime zest if desired.