Peel and dice the onion and add to a large casserole dish with 1 tablespoon of the olive oil. Soften over a medium heat for 5 minutes, then pour in the risotto rice. Stir for 2 minutes.
Pour in the white wine, stirring all the time, until the liquid has been absorbed.
Add the stock gradually, continuing to stir. Add 100ml at a time, stir and let it absorb, then add more stock until it has all been used.
Chop the asparagus spears into bitesize pieces, and when the stock has been aborbed add the asparagus to the pan. Simmer for 5 minutes over a low heat, then turn the heat off. Pour over the remaining tablespoon of olive oil then put a lid on the pan and leave it to sit for 6-7 minutes.
Meanwhile, preheat the oven to 180 degrees. Get a baking tray and split your parmesan into four small handfuls. Place on the baking tray with as much of a gap between each as possible, and put in the oven for 6-7 minutes until the parmesan is golden and bubbling. Remove from the oven and leave to cool.
To serve, top each bowl of risotto with a parmesan crisp.