Preheat oven to 180°C.
Fry the onions, chicken and garlic (in an ovenproof pot if you have one).
Once the chicken is almost cooked through add the mushrooms and fry for 2-3 mins.
Stir in the risotto then add the stock and season with salt and pepper.
Stir then put in the oven with a lid on for 25 mins.
Remove lid, stir in spinach and asparagus, put the lid back on and cook for another 10mins.
Sprinkle Parmesan on top to serve.