01 - Place the whole chicken breasts at the bottom of the slow cooker. Add the sliced carrots, diced onion, minced garlic, chicken broth, dried Italian herbs, salt, and black pepper. Stir gently to distribute the ingredients evenly.
02 - Cover the slow cooker and cook on low heat for 6 to 7 hours or on high heat for 3 to 4 hours. The chicken is done when it is tender enough to be easily shredded.
03 - Remove the cooked chicken breasts from the slow cooker and place them on a cutting board. Use two forks to shred the meat, then return the shredded chicken to the pot.
04 - Stir the evaporated milk (or half-and-half) and the cubed cream cheese into the slow cooker. Mix continuously until the cream cheese has melted completely and the broth is smooth and creamy.
05 - Add the refrigerated cheese tortellini and baby spinach to the mixture. Stir well, cover, and cook on high heat for an additional 15 to 20 minutes. Wait until the tortellini is tender and the spinach has wilted.
06 - Stir in the shredded Parmesan cheese just before serving. Taste the soup and adjust the seasoning with additional salt and pepper if desired. Serve hot.