Spray the inside of a large slow cooker with non-stick spray. Place the chicken breasts in the slow cooker, followed by the onion, rice, onion soup mix, beef broth, and can of French onion soup.
Cover with the lid and cook on LOW for 5 hours or HIGH for 3 hours, or until the rice is tender and the chicken is cooked through. Don’t overcook or the rice will be mushy.
Once cooked, place the slices of provolone and the fried onions on top. Cover with the lid and cook on LOW for 10 minutes to melt the cheese. Enjoy!