Add the steak chunks, salt, pepper, brown sugar, Worcestershire sauce, and avocado oil to a large bowl and stir until all the ingredients are combined and coated with marinade. Transfer the bowl to the refrigerator.
Preheat the air fryer to 400ºF. Toss the potatoes in oil, sea salt pepper, and thyme.
Add the potatoes to the air fryer and cook them for 16-18 minutes or until golden brown and cooked through.
While the potatoes are cooking, make the dressing. Place all of the ingredients for the dressing into a high-speed blender or food processor. Process until smooth. Set aside.
Once the potatoes are cooked, remove them from the air fryer.
Remove the steak from the fridge and let it sit at room temperature for 10 minutes.
Preheat the air fryer (if not heated already) to 400ºF. Add the steak chunks to the air fryer, be sure there is only one layer of steak. Do not stack the steaks on top of each other. Cook for 5-6 minutes or until crispy on the outside. You will need to cook the steak in batches. Repeat until all steak is cooked. Set aside.
Toss the romaine, cherry tomatoes, and onions in a large bowl.
Prepare the steak bowl. Evenly separate the steak, potatoes, and salad into 4-6 bowls. Top with dressing and enjoy.