Heat butter in a large saute pan set over medium heat. Add shallots and saute until translucent.
Add mushrooms and saute until cooked through. Add rice and stir until well coated.
Add 2 cups of chicken stock and simmer until liquid is absorbed, stirring continuously. Add remaining stock in small quantities (as above), stirring continuously until liquid is absorbed before adding more.
After about 10 minutes, add diced yellow bell pepper. Continue to cook. When the rice becomes creamy and the grains al dente, add cheeses, and stir well. Add cream, parsley, and adjust seasonings.