Place cubed chicken breast into the crock pot. Saute mushrooms and onions in butter until tender (optional), then dump into the crock pot with the chicken breast. Whisk together soups, chicken broth and seasonings in a medium sized bowl, then pour over chicken and veggies in the crock pot.
Turn crock pot to low and cook the chicken and soup mixture for 2-3 hours until chicken is just cooked through, then stir in the rice and cook for another 1.5 to 2 hours until the rice is fully softened and has soaked up all the moisture.
Sprinkle shredded cheddar cheese over top of the casserole at the last 5 minutes of cooking and allow to melt. Cool slightly and enjoy!
Notes
To keep the rice mixture from burning onto the sides of the crock pot, stir every half hour or so of the last hour of cooking.Additional chicken broth can be added if the rice seems dry and not fully cooked in the times given in the recipe card. The rice can also be cooked separately before adding to the casserole, but you may wish to reduce the amount of chicken broth added to the casserole. See below for step by step photos and additional notes.
Keyword Chicken and rice, casserole, slow cooker, cream of soups