Chop the shallots, bell pepper, and mushrooms into small pieces. Mince the garlic. In a large pot over medium to high heat, melt the butter and olive oil together and lightly season with salt and pepper. Add the shallots and bell pepper and cook for 2-3 minutes until beginning to soften. Stir in the mushrooms and garlic and cook another minute.
Then stir in the rice and cook for another 2-3 minutes. Add the wine and continue to cook uncovered on high heat for another 2 minutes. Then add the stock and bay leaves. Turn the heat down to low, cover and allow to cook for 45-50 minutes until rice is tender. Stir occasionally.
Uncover, remove the bay leaves, and allow to cook for another 5-6 minutes so the soup reduces just a little. During this time, in a small bowl whisk together the cornstarch and milk. Stir this into the soup and allow to thicken. Just before serving, stir in the Parmesan cheese and herbs and season with a little more salt and pepper as needed.
You can substitute the butter for more oil, the milk for a non-dairy milk, and simply skip the Parmesan or use a non-dairy alternative if you want to avoid dairy. I like to use a white wine in this, usually a chardonnay.