Place chopped onion and half of the wine into the bottom of the crock-pot. Add chicken, with half of the salt and half of the pepper, and the thyme sprigs. Add half of of the wine. Cover and cook on low setting 5-6 hours or until chicken is tender. Remove chicken to warm plate. Combine remaining ingredients in crock-pot, simmer on high setting about 5 minutes. Return chicken to crock-pot, lower cook setting to low and heat for about 15 minutes. Serve.