Combine eggs, sausage, chard (or arugula), tomato, scallion, Parmesan and basil in a large bowl.
Coat a nonstick 6-inch round cake pan with cooking spray. Pour the egg mixture into the pan.
Place the pan in the basket of an air fryer; cook at 340°F until set in the middle, 18 to 20 minutes. Let stand for 5 minutes. Garnish with Parmesan, scallions, basil and/or pepper, if desired.
