Heat 2 tbsp vegetable oil in a small saucepan over medium heat. Cook the ginger and garlic about 30 seconds. Mix in the soy sauce, brown sugar, and water. Turn heat to medium-high until sauce boils and thickens about 5 minutes. Remove from heat
Put the chicken or beef into a bowl and coat it well with the cornstarch. Allow the meat to absorb cornstarch about 12 minutes
Heat 1 cup vegetable oil in wok to 375 degrees F
Shake excess cornstarch off meat and place a few at a time in the hot oil, do not overcrowd. Cook for about 3 minutes until meat starts to brown and becomes crispy. Remove meat and drain on wire rack over baking sheet or on paper towels
Pour oil out of wok and heat over medium heat. Place meat slices back into pan and pour soy sauce mixture over meat, stir to combine. Add the cut green onions and bring to boil for about 3 minutes
Serve with rice or noodles if desired