Cut pork tenderloin into 1 to 1½ inch thick slices. Remove any excess visible fat if there is any.
In a mixing bowl combine, chicken broth and enough water to make 3 cups of liquid.
Stir in cream of mushroom soup and spices; garlic powder, onion flakes, mushroom seasoning, salt and pepper.
Stir until lumps are gone.
Stir in sliced mushrooms.
Pour over pork tenderloin in the slow cooker.
Drop cubed butter on top.
Cover and cook for 7 hours on low.
Remove pork from slow cooker and use two forks to shred pork. Set aside.
Add 1 cup of boiling water and 2 cups white rice to the slow cooker.
Return pork to the slow cooker.
Stir to combine everything together. Cover and increase heat to high.
Cook for another 45 to 60 minutes until rice is cooked through and soft.
Remove lid and stir in the shredded cheese.
Cover and cook for another 5-10 minutes or until the cheese is melted.