Prepare the slow cooker by spraying nonstick spray inside.
Stir the rice, carrots, shallot, and Dijon mustard together in the bottom of the cooker.
Arrange the chicken over the rice mixture.
Sprinkle them with garlic powder, thyme, salt, and pepper evenly.
Pour the chicken broth over the top, allowing it to cover everything.
Turn the slow cooker on to low heat.
Cook for 6 to 7 hours, until the rice and chicken are tender and fully cooked.
Keep an eye on the liquid level and ensure everything is well-cooked.
Before serving, top the dish with cheese and parsley, letting the cheese melt.
This adds a flavorful finish to your casserole.