Preheat the oven to 350 degrees F (175 degrees C).

Heat oil in a heavy Dutch oven over medium heat. Add chicken, season with salt and pepper, and cook, stirring occasionally, until browned all over, 8 to 10 minutes. Add potatoes, carrots, celery, onion, garlic, and bouillon, then pour in water. Stir to combine, cover, and bring to a boil.

Transfer the covered Dutch oven to the preheated oven and cook until vegetables are tender and chicken is no longer pink at the bone and the juices run clear, about 45 minutes. An instant-read thermometer inserted near the bone should read 165 degrees F (74 degrees C).