In a large oven-safe pot, combine Cream of Mushroom, Better than Bouillons, Water, Onion, and Seasonings. Whisk until well combined.
Place the whole chicken breast side up into the pot. Cover with a lid and cook in the oven for 3-4 hours or until the chicken easily falls off the bone.
Once the chicken is cooked, transfer the pot to the stovetop over medium-low heat.
Remove the chicken from the pot onto a plate. The chicken will naturally break apart into the soup. Use a slotted spoon to ensure all meat and bones are removed, while leaving the onions in the soup.
Shred the chicken into large chunks (or smaller, based on preference) and return it to the soup.
Bring the soup to a low boil.
Dumplings:
Open the can of biscuits and place them on a cutting board. Cut each biscuit into quarters and toss them in flour, ensuring each piece is coated and not sticking to others.
With the soup at a low boil, drop the biscuit pieces into the pot. Cook for 15-20 minutes or until the middle of the biscuits is fully cooked. Halfway through, gently push the dumplings into the soup and break apart any that may have stuck together.
Once the dumplings are done, taste the soup and adjust the seasoning as needed.