Step 1In a small saucepan, combine the vinegar, soy sauce, sugar and chile flakes and bring to a boil over high heat, stirring once or twice. Remove from heat and set aside to cool. This makes about 3/4 cup sauce, more than is needed for the remainder of the recipe; the sauce will keep for up to 2 weeks, refrigerated.
Step 1Fill a large pot with enough oil to come up about 4 inches and heat the oil until it reaches 375 degrees. Fry the broccoli, in small batches until the pieces are a light brown color, 30 seconds to 1 minute. Drain the pieces well, and repeat until all of the broccoli is fried.
Step 2Place the broccoli in a bowl and sprinkle over the sauce, tossing the broccoli to coat. Drain the pieces and place on a platter, garnishing with the green onion. Serve immediately.