In your slow cooker, place the boneless, skinless chicken breasts, chicken broth, diced onion, minced garlic, salt, and pepper. Stir everything together briefly to ensure the chicken is well-coated in the flavorful broth. Set your slow cooker on low for 6-7 hours or high for 3-4 hours until the chicken reaches an internal temperature of 165°F and is easily shreddable.

Once the cooking time is up, carefully remove the chicken breasts from the crockpot using tongs or a slotted spoon. With two forks, shred the chicken into bite-sized pieces. Return the shredded chicken back into the pot, mixing it with the remaining broth and vegetables.

Stir in the uncooked gnocchi and chopped spinach to the crockpot. Pour in the heavy cream. Close the lid and set the slow cooker on high for an additional 20-30 minutes, or until the gnocchi floats to the top and is tender to the bite.

After the noodles are cooked, give the soup a gentle stir once more. Taste and adjust seasoning as needed before serving hot in bowls.