Place the steak in a medium-sized bowl and toss with the soy sauce, garlic powder, and onion powder. Add the cornstarch and mix it in, so the beef is coated. Set aside.
Preheat the air fryer to 375 degrees F, air fryer setting. Add the broccoli to the basket and spray with cooking spray.
Shake the basket to coat the broccoli and cook for 8 minutes, shaking the basket every 2 minutes until tender-crisp and starting to brown. Set aside.
Spray the basket with cooking spray. Add the beef to the basket in a single layer, spray with cooking spray. Air Fry for 15 minutes, shaking the basket every 5 minutes, and coating with more cooking spray. Beef will be cooked through and lightly crispy.
For the sauce, in a small bowl, whisk together the light soy sauce, beef stock, brown sugar, cornstarch, garlic, rice vinegar, and ginger. Set aside.
In a large skillet over medium heat, add the cooked beef and broccoli to the pan. Add the sauce, and toss everything to coat. Cook until the sauce is thickened, about 2 minutes.
Serve with scallion garnish. Plate, serve, and enjoy!