In a small bowl, combine the cornstarch and broth until a smooth slurry forms. Stir in the soy sauce, hoisin sauce and sesame oil, and set the bowl aside.

In a large nonstick skillet or wok, stir-fry the beef strips in 1-½ teaspoons of hot olive oil until they're no longer pink. Remove them from the pan and keep them warm. Editor's Tip: Any type of stir-frying requires a very hot pan to get a good sear and cook quickly. So get your wok or skillet good and hot over high or medium-high heat. Add the oil and let that get hot, too. Otherwise, the meat will steam and turn gray rather than develop good brown color. Cook the beef in batches so that you don't crowd the pan. If using a skillet, spread the meat into a single layer and let it cook undisturbed until you get a good sear. Transfer the meat to a plate or wide dish; the meat will steam if piled up.

In the same skillet, stir-fry the onions in the remaining olive oil until they're crisp-tender, three to four minutes.

Stir the cornstarch mixture and add it to the pan. Bring the sauce to a boil, and cook and stir it until it has thickened, about two minutes. Editor's Tip: If the sauce isn't thickening as much as you'd like, make a slurry by dissolving 1 teaspoon cornstarch with 1 teaspoon water. Stir the slurry into the sauce and let it simmer and thicken before you return the beef to the pan.

Reduce the heat and add the beef. Cook until the beef is just heated through. Serve the stir-fried beef with rice. Editor's Tip: Some juices will collect on the plate as the stir-fried meat rests. Add that flavorful liquid back to the pan along with the beef.