Heat 1 tablespoon of the vegetable oil in a medium saucepan over medium-high heat. Add 1/2 the onions and cook until slightly softened but not browned, about 2 minutes. Add the garlic and celery and cook for 1 minute, stirring constantly. Add 2 1/2 cups of the beef (or chicken) broth and bring to a boil.
In a small bowl, whisk together the remaining 1/2 cup beef broth, cornstarch, and soy sauce. Add the cornstarch mixture and the corn syrup to the saucepan and return the mixture to a boil. Reduce the heat and simmer for 5 minutes, or until the gravy is slightly thickened.
Add the beef, chicken, or pork, stirring until warmed through. Keep warm until ready to serve.
When ready, serve over chow mein noodles, or combine noodles and sauce and serve over the bottom of a hamburger bun. Cover with the top of the bun for a chow mein sandwich.
Cook your beef (or whatever protein you're using) with 1/2 cup of onion and the celery.