• In a medium mixing bowl, combine beef and marinade ingredients. Let marinate while you prepare the other ingredients.
• Meanwhile, in a small bowl, combine sauce ingredients and set aside.

Stovetop

• In a shallow dish, add potato starch, lightly coat each piece of beef.
• In a wok or large frying pan on medium high heat, add 2 tablespoons cooking oil. Add half of the beef. Cook for one minute to sear one side. Flip and cook until the beef is evenly browned and crispy. Remove and repeat with the remaining beef.
• Turn the heat down to medium, add garlic, ginger and chilis if using, cook for 30 seconds, until fragrant. Add the sauce and let simmer for about 5 minutes. In the same bowl, dissolve cornstarch in cool water to make a slurry. Add the slurry to the sauce and cook until the sauce starts to simmer and thicken.
• Add the cooked beef until the beef is well covered with the sauce and heated through.
• Turn off the heat. Stir in green onion.

Air Fryer

• In a shallow dish, add potato starch, lightly coat each piece of beef and place in a single layer in an air fryer. Spray the beef with cooking oil.
• Air fry for 10 mins at 400°F, stirring once at about halfway mark. Cook until the beef is evenly browned and crispy. If using a smaller air fryer, you may need to cook in multiple batches at 10 minutes per batch.
• Meanwhile, in a small bowl, combine sauce ingredients and set aside.
• In a wok or large frying pan on medium heat, add 1 tablespoon cooking oil. Add garlic, ginger and chilis if using, cook for 30 seconds, until fragrant. Add the sauce and let simmer for about 5 minutes. In the same bowl, dissolve cornstarch in cool water to make a slurry. Add the slurry to the sauce and cook until the sauce starts to simmer and thicken.
• Add the cooked beef until the beef is well covered with the sauce and heated through.
• Turn off the heat. Stir in green onion.