1 pound skirt steak, sliced thinly (flank steak or beef tenderloin will work too)
1/2 cup corn starch
2 tablespoons vegetable oil, plus more for frying
1 large white onion, finely chopped
1 1/2 cups carrots, julienned (can use grated or shredded carrots too)
3 cloves garlic, minced
1 tablespoon fresh ginger, grated
1/2 teaspoon dried red chili flakes
1/2 cup light soy sauce
2 tablespoons rice vinegar
1 tablespoon sesame oil
1/2 teaspoon black pepper
2 tablespoons sesame seeds, toasted
1/4 cup green onions, thinly sliced