Chinese Beef and Broccoli

INGREDIENTS

• 1 pound flank steak, sliced thin crosswise
• 1½ pounds broccoli, cut into florets (discard stems or save for another use)
• 1 tablespoon vegetable oil
• 1 (2-inch) piece of fresh ginger, minced
• 3 cloves garlic, minced
• :
• 2 tablespoons cornstarch
• 1 tablespoon soy sauce
• 2 teaspoons rice vinegar
• ½ teaspoon sesame oil
• 8 tablespoons water
• 2 tablespoons soy sauce
• 2 tablespoons oyster sauce
• 2 teaspoons cornstarch
• 1 teaspoon dark brown sugar