If you’re using the oven, preheat it to 180°C.
Cut the asparagus in to 2cm pieces. Chop the mushrooms too.
Put them in a frying pan, add some olive oil and a pinch of dried oregano and gently cook for 5 minutes, until vegetables are tender. Set aside to cool.
Whisk the eggs in a mixing bowl with some salt and pepper. Set aside.
Evenly divide vegetables between 4 silicon muffin cups. Scatter the cheese over the vegetables, then pour over the eggs evenly.
Put them in the air fryer (you can top them with a pinch of grated cheese, if liked) and cook for 20 minutes.
In the oven, bake them for 25-30 minutes or until golden brown.
Serve warm.