Slace 2 pounds flank steak against the grain into thin strips. Cut it as thin as you can and place the strips in a mixing bowl or large plastic bag.
Add in 1 cup finely grated Asian pear, ⅓ cup soy sauce, 2 tablespoons sesame seeds, 1 tablespoon sesame oil, 2 teaspoons oyster sauce, 3 cloves minced garlic, ½ teaspoon crushed red pepper flakes, and ½ teaspoon ground ginger
Toss together until well coated. Let marinate in the fridge for 1 hour.
After marinating, heat a large heavy skillet or wok over high heat. Use tongs to transfer the steak to the hot skillet. Cook on high, tossing frequently until cooked through, which will take about 3 to 5 minutes in a skillet. In a quality wok, this may take less than 2 minutes.
Serve hot sprinkled with ½ cup sliced green onion.
