Easy Mongolian Beef

Bahan-bahan (4 porsi)

• 2 teaspoons vegetable oil (plus 2 tablespoons, divided)
• ½ teaspoon minced fresh ginger
• 4 cloves garlic (finely minced)
• ½ cup less sodium soy sauce
• ¼ cup water
• ½ cup brown sugar (packed)
• 1 pound flank steak (or your favorite cut of beef, thinly sliced)
• ⅓ cup cornstarch
• 2 g reen onions (sliced)