Roast cauliflower in an air fryer or oven. If using frozen cauliflower DO NOT defrost first.
Preheat air fryer to 390 °F or oven to 450 °F.
Use hands to coat the nooks and crannies of the cauliflower florets with olive oil. Season with salt and pepper.
Cook for about 20 minutes shaking the air fryer basket or flipping on the sheet pan halfway through.
While the cauliflower is roasting, make the sauce. Combine mayonnaise, sour cream, lime juice, garlic and cayenne pepper in a small bowl.
Add cooked cauliflower to serving bowl and toss with sauce.
Fold in feta cheese.
Sprinkle with garnish, if using, and enjoy!