Mix the flour with parsley, salt, spices, and seasonings, then coat each piece of chicken thoroughly while reserving the remaining seasoned flour.

Heat oil in a skillet and sear the chicken pieces on both sides until golden brown, then remove them from the pan and set aside.

In the same pan, melt butter and sauté the onion and celery until soft, then add garlic and cook briefly until fragrant.

Sprinkle the reserved seasoned flour over the vegetables, stir well, then add broth concentrate and gradually whisk in milk and water until a smooth sauce forms.

Rinse the rice until the water runs clear, then add it to the prepared casserole dish along with water and the prepared sauce, mixing everything evenly.

Arrange the seared chicken pieces on top of the rice mixture, cover the dish tightly with foil, and bake until the rice is tender and the chicken is nearly cooked through.

Remove the foil and continue baking at a higher temperature until the chicken is fully cooked and the top becomes golden brown.

Let the casserole rest before serving so the sauce thickens and the flavors settle.