Slow cooked chicken and rice casserole

I think I cooked mine too long and the rice turned a bit mushy, I'll try it again one day!

1 1/2 cups chicken broth
1 1/2 cups milk
3/4 cup flour
spray oil
1 1/2 cups brown rice
1 diced onion
225g sliced mushrooms
3-4 chicken breasts
1/2 tsp onion powder
1/4 tsp black pepper
1/4 tsp paprika

Combine chicken broth with 1/2 cup of the milk in a saucepan, heat on med
Whisk remaining milk with flour, when broth boils gradually stir into broth
Cool
Spray crockpot
Add rice, onion, mushroom and seasonings to crockpot
Mix in broth, lay chicken on top

Cook on LOW for 8 hours or HIGH for 4 hours