1. Rinse chicken and pat dry with paper towels. Coat the external surface of the chicken with olive oil. Combine oregano, thyme, pepper, paprika and salt in a bowl. Place chicken into the bowl and toss lightly to coat with the spices. Rub the spices all over the chicken to make sure it is coated. Insert garlic into the cavity of chicken. Add more salt and pepper if needed.
2. Place the celery stalks across the bottom of crock pot. Add chicken broth, just enough to cover celery. This will prevent the chicken from browning to much at the bottom. Place chicken is slow cooker breast side up.
3. Cover and cook on low for about 4-6 hours or until the chicken reaches 165 degrees internal temperature and vegetables soften. Check for completeness using a meat temperature or insert a fork to ensure juices are clear.
4. Carefully take chicken out from the slow cooker. Brown the chicken by placing it in a large roasting pan and broiling until desired browness had been acheived.
5. You can add mixed select veggies to the slow cooker 30 minutes before you are ready to eat.