One pot chicken and mushroom risotto

Name: One pot chicken and mushroom risotto
Prep time: 10 min
Cook time: 55 min
Total time: 1 h 5 min
Cuisine: Italian
Ingredients: 50g butter; 85g smoked bacon lardons; 1 large onion halved and finely chopped; 250g chestnut mushrooms thickly sliced; 300g arborio risotto rice; 150ml dry white wine; 1.4l hot chicken stock; 140g cooked chicken chopped; 50g grated parmesan plus extra to serve (optional); ½ small pack of flat-leaf parsley chopped