Korean Beef Bulgogi

Ingredients

• 2 pounds flank steak
• 2 tablespoons vegetable oil (divided)
• 2 green onions (thinly sliced)
• 1 teaspoon toasted sesame seeds
• 1/4 cup reduced-sodium soy sauce
• 1 tablespoon rice vinegar
• 3 tablespoons light brown sugar
• 2 tablespoons sesame oil
• 5 cloves garlic (minced)
• 1 tablespoon freshly grated ginger
• 1/2 cup Asian pear (grated)
• 1/8 teaspoon red pepper flakes