Place the sliced steak in a medium bowl and toss with the soy sauce, garlic powder, and onion powder. Sprinkle in the cornstarch and mix until the beef is evenly coated.
Preheat the air fryer to 375°F for 3–4 minutes on the air fry setting.
Add the broccoli to the basket, spray with cooking spray, and shake to coat. Air fry at 375°F for 8 minutes, shaking every 2 minutes, until tender-crisp and starting to brown. Transfer to a bowl.
Spray the basket. Add the beef in a single layer (work in batches if needed) and spray the top. Air fry at 375°F for 15 minutes, shaking every 5 minutes and re-spraying, until cooked through with crisp edges.
Whisk together the light soy sauce, beef stock, brown sugar, cornstarch, garlic, rice vinegar, and ginger in a small bowl.
Add the beef and broccoli to a large skillet over medium heat. Pour in the sauce and toss to coat. Cook 2 minutes, until thickened and glossy.
Garnish with scallions and serve immediately over rice.