Add chicken thighs to bottom of slow cooker insert. Whisk together sauce ingredients and pour over chicken. Cover and cook on LOW for 6-8 hours, or HIGH for 3-4 hours.
Remove chicken from slow cooker, shred, then add back to slow cooker with juice and sauce.
Add broccoli, snow peas, carrots, bell pepper and water chestnuts, and stir. Cover and cook on HIGH for 15 minutes, until vegetables are tender.
While vegetables are cooking, boil and drain pasta per package directions, then add to crockpot with chicken and vegetables. Stir well, then serve with garnishes, if desired.