1Scatter onion in the bottom of a large slow cooker then top with chicken. Season with oregano, salt, and pepper.
2Pour over soup and broth then add thyme and bay leaf. Cover and cook on high until the chicken is cooked through, about 3 hours.
3Discard thyme and bay leaf, then shred chicken with two forks. Stir in celery, carrots, peas, and garlic. Cut biscuits into quarters or smaller, but large enough to be bite sized. Stir them into chicken mixture. Spoon liquid over any biscuits at the top.
4Cook on high until vegetables are tender and biscuits are cooked through, stirring every 30 minutes, about 1 hour to 1 hour 30 minutes more.