rinse shrimp, pat completely dry and marinate in cornstarch and 1/2 tsp kosher salt for 5 minutes. heat your wok or large skillet over high heat. when wok is hot, add 2 tbl cooking oil. when oil is hot and just starting to smoke, add shrimp. fry until they are half-done, approximately 1-2 minutes. remove from wok, leaving the oil in the wok.
turn heat to medium-high. add the garlic, fry for 10 seconds. add the brandy, salt, sugar, butter. cook sauce for 1 minute to thicken slightly. add the half-cooked shrimp and green onion. fry until shrimp are cooked through, about 2 minutes (depends on size of your shrimp)