Crock-Pot Chicken and Dumplings

• 1 onion, chopped
• 1 1/4 lb. boneless skinless chicken breasts
• 1 tsp. dried oregano
• Kosher salt
• Freshly ground black pepper
• 2 (10.5-oz.) cans cream of chicken soup
• 2 c. low-sodium chicken broth
• 4 sprigs fresh thyme
• 1 bay leaf
• 2 stalks celery, chopped
• 2 large carrots, peeled and chopped 
• 1 c. frozen peas, thawed
• 3 cloves garlic, minced
• 1 (16.3-oz.) can refrigerated biscuits

Directions