Beef Stir-Fry in Soy Glaze with Green Onions

Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the sliced beef and stir-fry until browned and cooked through, about 3-4 minutes. Remove the beef from the pan and set it aside.
Sauté the Vegetables:

In the same pan, add more oil if necessary, then sauté the minced garlic, grated ginger, bell peppers, and onions for 2-3 minutes, until tender-crisp.
Prepare the Sauce:

In a small bowl, mix together soy sauce, oyster sauce, hoisin sauce, brown sugar, rice vinegar, and beef broth. Pour this sauce mixture into the pan with the vegetables and bring to a simmer.
Thicken the Sauce (Optional):

If you want a thicker sauce, mix the cornstarch with a little water to make a slurry, then add it to the sauce. Cook for an additional 1-2 minutes, until the sauce thickens.
Combine the Beef and Sauce:

Return the cooked beef to the pan and toss it in the sauce until it is evenly coated.
Garnish and Serve:

Garnish the stir-fry with freshly sliced green onions and sesame seeds (if using). Serve with steamed rice or your choice of Asian side dishes.
Serving and Storage Tips: