Brush 1 teaspoon olive oil around top ridge of mushroom caps.
Preheat air fryer at 180°C for 3 minutes.
In a medium bowl, combine mushroom stems, squash, nutritional yeast, salt, remaining olive oil and tomato paste.
Distribute and press mixture into tops of mushroom caps.
Place stuffed mushrooms in ungreased air fryer basket.
Cook for 5 minutes.
Transfer mushrooms to a medium plate and garnish with parsley.
Serve.