1 pound flank steak, thinly sliced against the grain
2 teaspoons oil, divided
1 tablespoon, plus 1/4 cup cornstarch
2 fresh tangerines or mandarin oranges
1 tablespoon sugar
1 tablespoon hot water
1/3 cup vegetable oil, for frying the beef
1/2 teaspoon minced ginger
1 small pod from a whole star anise (if need be, substitute with a pinch of five spice powder)
5 pieces dried tangerine or mandarin orange peels
5 dried red chili peppers (optional)
1 clove garlic, chopped
3 tablespoons light soy sauce
1 1/2 tablespoons brown sugar
1 teaspoon cornstarch, mixed with 1 tablespoon water
2 scallions, cut into 1-inch slices on the diagonal
Marinate the beef for 1 hour in 1 teaspoon oil and 1 tablespoon of cornstarch and set aside. Lightly scrub the tangerines with a vegetable brush under running water to remove wax and/or pesticides and towel dry. Peel the tangerines (reserving the peels) and squeeze 1/3 cup juice from the fruit.
Scrape as much of the white pith from the peels as you can, until you see just the skin, and julienne the peels into thin slivers. Set aside along with the juice. Then make a simple syrup by dissolving 1 tablespoon of sugar into 1 tablespoon of hot water.
Heat a saucepan or wok over low heat and add 1 teaspoon of oil and the tangerine peel slivers. Lightly toast the peels by tossing in the oil for about 30 seconds, and add the simple syrup. Continuing stirring the peels until the simple syrup evaporates and clings to the peels. Transfer the candied peels to a bowl along with any infused oil, and set aside.
Dredge the pieces of meat individually in the remaining ¼ cup of cornstarch until lightly coated, and heat 1/3 cup oil in a clean wok over high heat. Just before the oil starts to smoke, spread the flank steak pieces evenly in the wok, and let sear for 1 minute. Flip the steak over and let the other side sear for another 30 seconds. Transfer to a sheet pan, and tilt it slightly to let the oil drain to one side (lean it on a cookbook or cutting board). The beef should be seared with a nice crusty coating.
Drain the oil from the wok, leaving about 1 tablespoon behind, and turn the heat to medium-high. Add the ginger, star anise or five spice powder, dried tangerine peels and dried chili peppers, if using. (We have a whole star anise pictured in our photos, but the recipe calls for only one pod. After tasting the finished product, we felt that a whole star anise may have been too overwhelming for the dish.)
After about 15 seconds, add the garlic. Stir for another 10 seconds, and add the soy sauce, tangerine juice and brown sugar. Bring the sauce to a simmer, stirring occasionally.
Let the sauce simmer for about 2 minutes and slowly stir in the cornstarch slurry mixture–until the sauce coats the back of a spoon. Add the beef, candied tangerine slivers with the infused oil, and the scallions. Toss everything for another 30 seconds until all of the beef is well-coated.
There should be almost no liquid, as the sauce should be clinging to the beef. If you still have too much sauce, increase the heat slightly and stir-fry until thickened. If the sauce is too thick, add a little bit of hot water to thin it out.