Crockpot chicken and dumplings

4 skinless, boneless chicken breast halves
2 Tbsp. Butter
2 (10.75 ounce) cans condensed cream of chicken soup...
1 onion, finely diced
2 (10 ounce) pkgs, refrigerated biscuit dough, torn into pieces

1. Place the chicken, butter, soup, and onion in a slow cooker, and fill with enough water to cover.
2. Cover, and cook for 5 to 6 hours on High. About 30 minutes before serving, place the torn biscuit dough in the slow cooker. Cook until the dough is cooked through.