Heat a large pot over medium-high heat (I used a pasta pot). Add the walnuts and cook for 5 minutes to toast, stirring occasionally. Remove the walnuts from the pan and coarsely chop. Set aside.

Add the olive oil to the pan, swirling to coat. Season the chicken with 1/4 teaspoon salt and 1/4 teaspoon pepper. Add the chicken to the pan and cook for 4 minutes. Flip the chicken and cook for 3 minutes. Remove and add to a plate to reserve. (The chicken won’t be cooked through yet).

Add the rice, onion, carrots, celery, and thyme to the pan.

Cook for 3 minutes, stirring to coat the rice.

Add the remaining 1/4 teaspoon salt and 1/4 teaspoon pepper as well as the chicken stock and 1 cup water. Scrape the pan with a wooden spoon to loosen all the browned bits. Reduce the heat to low, cover, and cook for 45 minutes at a low simmer.

After 45 minutes, return the chicken thighs to the pan, pushing them down into the rice.

Top with raisins and Brussels sprouts.

Cover and return to a simmer, cooking for another 12 minutes or until the liquid is absorbed and the chicken is fully cooked through.

Remove the chicken and add to a plate. Stir the walnuts and vinegar into the rice mixture.

Serve the rice mixture with the chicken. I’d suggest adding a bit of lemon juice to finish off the dish.