Toss diced red potatoes with 1 tbsp olive oil, salt, and your preferred seasonings. Preheat air fryer to 400 degrees F. Spread potatoes in a single layer and air fry for 16 to 18 minutes, shaking the basket halfway through, until golden and crispy.

While potatoes cook, heat the remaining 1 tbsp olive oil in a large skillet over medium-low heat. Add diced onions and cook for 10 to 15 minutes, stirring occasionally, until deeply golden and caramelized.

Push onions to the side or remove to a plate. Increase skillet heat to medium-high. Add ground beef and smash flat with a spatula. Cook undisturbed for 2 to 3 minutes to build a crust, then break apart and cook another 3 to 4 minutes until browned through. Drain excess fat and season with salt and pepper while hot.

In a small bowl, whisk together mayo, ketchup, Dijon mustard, and Cajun seasoning until smooth. Adjust seasoning to taste.

Build each bowl with crispy potatoes as the base. Top with smashed beef, caramelized onions, and shredded cheese. Drizzle generously with special sauce. Finish with pickles and leafy greens if using.