Place 1 tablespoon of oil into a pan over medium heat. Saute garlic for 30 seconds, or until fragrant. Add the ginger, soy sauce, water, and brown sugar. Simmer for 3-5 minutes, or until the sugar is fully dissolved and the sauce has slightly thickened.
Slice beef into 1/2 inch thick sliced against the grain. Season liberally with salt, onion powder, garlic powder, and Sweet Ginger Garlic seasoning. Lightly coat the seasoned beef in corn starch, and let sit while you preheat your pan.
Add a few teaspoons of oil to a non-stick pan and place it over medium-high heat. Lightly saute the vidalia onions until they are tender. Remove, add enough oil to thinly cover the bottom of your pan, and turn the heat up to almost high. You want the oil JUST under the smoking point.
When the pan and oil are hot, add the beef. Cook for a minute or two, and then turn. You want to sear the sides and add some color, but not cook it all the way through. Remove from the pan once seared and drain off excess oil into a heatproof container.
Add beef and onions back into the pan and pour the sauce in. Bring the container up to a high simmer, and cook until the sauce is thickened. Stir in green onions last. Serve hot over rice. Sprinkle with a little additional Sweet Ginger Garlic Seasoning if desired.