Heat oil in a heavy-bottomed pan over medium heat. Brown
chicken thighs on both sides. Remove chicken and drain all but 1 tablespoon of fat from pan. Sauté shallots on medium-low heat until translucent, but not browned. Add white wine, chicken stock and garlic cloves. Add chicken back to the pan and bring to a simmer. Cook covered until chicken is tender, about 30-45 minutes. Remove chicken from the pan again and bring liquid to a boil; reduce by 3⁄4. Once the liquid has thickened, add mustard and capers. Season with salt and black pepper. Add butter to enrich. Add chicken and warm through.