In a large, heavy-based pan, saute chicken with 1 tablespoon of olive oil on high heat. Season with salt and pepper. Remove chicken into a bowl once browned and almost cooked through.
To make the sauteed mushrooms, add olive oil, garlic and mushrooms in the same pan. Saute on medium-high heat until mushrooms caramelised and nutty. Remove mushrooms and set aside.
Again, in the same pan (note 4), sweat leeks with the remaining tablespoon of olive oil, a minced clove of garlic. Cook on low heat, stirring constantly until leeks are soft. About 5 minutes.
Add arborio rice, lightly toast the rice by constantly stirring on medium heat for 1 minute.
Now, reduce heat to low. Add 1 cup of hot stock into the pan, stir constantly until the stock has been fully absorbed before adding the next cup of stock. (note 5) Repeat until all of the stock has been absorbed. This will take about 18 minutes.
By now, the risotto should be creamy and soft on the outside yet slightly firm on the inside. Stir browned chicken into the risotto, including its juices (flavour!)
Continue to stir the risotto until chicken is cooked through, taste and adjust for seasoning. This will take about 3 minutes. If the risotto is a little too thick, add a little water to loosen.
To serve, top with sauteed mushrooms and lots of parmesan cheese!