Crispy Mongolian Beef

Quick to make in under 30 minutes,, this recipe is perfect for a weeknight dinner which doesn’t break the bank. It has a tangy, rich sticky sauce which coats the crispy beef and is so much better than takeaways! Ingredients below:
Music - Epidemic Sound: Mountains of Himalaya - Marc Torch
INGREDIENTS
1 kg beef tenderloin/beef chuck, cut into strips
1/2 cup cornstarch/cornflour
Neutral oil, for deep frying
FOR THE SAUCE
2 tbsp cooking oil
1 red onion, sliced
1 tbsp finely chopped ginger
1 tbsp finely chopped garlic
1/2 cup soy sauce
1/2 cup rice vinegar
1/2 cup water
1 tsp hoisin sauce
1/2 cup brown sugar
1 tsp cornstarch, diluted in 3 tsp water
1 tsp red chili flakes (optional)
1/2 cup green onion, chopped into 1-inch pieces