1.Pour stock into medium saucepan and bring to a slow simmer. Keep warm.
2.Heat oil in a large heavy-based saucepan on medium. Saute mushroom 1-2 minutes. Set aside. In same pan, saute onion 3-4 minutes, until tender. Add rice, stirring 1 minute to coat well.
3.Pour in wine and stir 1 minute until absorbed. Add hot stock, 1 cup at a time, stirring until all liquid has been absorbed before adding the next cup – this will take 15-20 minutes. Rice should end up creamy with a slight bite.
4.Remove from heat. Stir chicken, peas, mushroom, parmesan, butter and lemon through. Season to taste. Set aside, covered, for 2 minutes, then serve with extra grated parmesan, parsley and crusty bread.