Trim excess fat or sinew from 1/2 pound beef sirloin steak and cut into bite-sized pieces. Place the steak bites in a gallon-sized resealable bag or shallow bowl.
Add 1 tablespoon lemon juice, 1 1/2 teaspoons olive oil, 1 1/2 teaspoons Worcestershire sauce, 1 1/2 teaspoons apple cider vinegar, 1/2 teaspoon onion powder, 1/2 teaspoon garlic powder, 1/2 teaspoon salt and 1/4 teaspoon black pepper. Toss to coat, then seal or cover. Refrigerate for 1 to 8 hours to marinate.
In a small mixing bowl, toss 16 ounces gnocchi with melted butter and 2 teaspoons minced garlic.
Preheat the air fryer to 400°F (200°C). Add the gnocchi to the air fryer basket and cook for 5 minutes.
Give the air fryer basket a shake to toss and then add in the steak bites, discarding any excess marinade. Cook for an additional 5 to 6 minutes for medium rare and up to 10 minutes for well done.
Serve immediately, with 2 tablespoons freshly grated parmesan cheese for sprinkling on top, if desired.