Set Instant Pot to Saute. Add oil.
Soften onion and garlic in the oil for a few minutes.
Add the rice and and coat in the oil.
Now tip in the wine and stock. And the chestnuts too but not the meat, it is already cooked so you will add that last.
Secure lid. Press Cancel and set to Rice for 10 minutes.
Let it stay on the Keep Warm setting once cooked. Release steam and stir in the meat and grated parmesan, stirring well to release the creaminess. You may like to add a splash of boiling water to loosen it; its up to you. Wait until the meat is thoroughly heated through before serving.
Serve with a green salad, a drizzle of extra virgin olive oil and some more parmesan.