1. Line a small 15 cm rectangular baking tin with baking paper.
  2. In a bowl, mix eggs, milk and salt and pepper. Heat the oil in a frypan and sauté the zucchini, asparagus, mushrooms, onion, and baby spinach for a few minutes. Place into the prepared baking tin and pour egg mixture over the vegetables. Sprinkle with cheddar and feta.
  3. Preheat the air frying oven to 160°C and turn the timer dial to 5 minutes.
  4. Once the ‘HEATING’ light goes off, turn the timer dial to 15 minutes.
  5. Place the baking tin into the Air Chef basket and allow to cook.
  6. Once the frittata has finished cooking, remove from the air frying oven and allow to cool before serving. Garnish with fresh chives.