Pat sweet potato fries completely dry with paper towels until no surface moisture remains.
In a mixing bowl, toss fries with avocado oil, cornstarch, salt, black pepper, and cayenne until evenly coated.
Arrange fries in a single layer in the air fryer basket; use a foil sling if your basket is small to prevent crowding and drips.
Set air fryer to 380°F and cook for 12 minutes.
At the 6-minute mark, pause and shake the basket to flip fries for even browning.
After 12 minutes, add black beans and shredded cheese over the fries.
Air fry 3 more minutes at 380°F until cheese is fully melted and edges are golden.
Carefully remove the basket with tongs.
Top with pico de gallo, avocado slices, red onion, jalapeños, sour cream, cilantro, and green onions.
Serve immediately while fries are hot and crispy.