Preheat your oven to 350°F and gather all the ingredients.
Preparing everything in advance will make the process smoother and faster.
Combine the rice, carrots, shallot, and Dijon mustard in a mixing bowl.
Mix them well so that the mustard coats everything evenly.
Place the mixture in a greased baking dish.
Layer the shredded chicken on top of the rice mixture.
Sprinkle garlic powder, thyme, salt, and black pepper over the chicken.
Pour chicken broth over the chicken and rice.
Cover the dish tightly with aluminum foil to keep the moisture in.
Bake in the preheated oven for about 45 minutes until the rice is tender.
Remove the foil, sprinkle Gruyere and Parmesan cheese over the top.
Return to the oven uncovered for an additional 10-15 minutes, until the cheese is bubbly and golden.