Asian beef and broccoli

Ingredients

• 1 beef Flank Steak (about 1-1/2 pounds)
• 2 tablespoons cornstarch, divided
• 2 teaspoons seasoned rice vinegar
• 1 tablespoon reduced-sodium soy sauce
• 1 tablespoon oyster sauce
• 1 teaspoon sesame oil
• 4 teaspoons vegetable oil, divided
• 1/2 cup thinly sliced onion
• 2 tablespoons minced garlic
• 2 tablespoons minced fresh ginger
• 2/3 cup cold water
• 1/3 cup reduced-sodium beef broth
• 2 tablespoons reduced-sodium soy sauce
• 1/2 teaspoon pepper
• 1 pound broccoli florets, cooked
• 3 cups cooked jasmine rice or cooked rice noodles
• Toasted sesame seeds, sesame oil (optional)