Place the chicken breasts on the bottom of a large slow cooker (6-quart size recommended).

In a medium bowl, whisk together the diced tomatoes (undrained), tomato sauce, Italian dressing mix, minced garlic, dried basil, salt, and pepper.

Pour the tomato mixture evenly over the chicken breasts in the slow cooker.

Cover and cook on low for 6 to 7 hours, or on high for 3 to 4 hours, until the chicken is tender and easily shreddable.

Carefully remove the chicken breasts from the slow cooker and place them on a cutting board. Shred the chicken using two forks or leave them whole, depending on preference.

Return the shredded chicken to the slow cooker. Reduce the heat to 'Warm' if necessary. Add the cubed cream cheese and heavy cream to the sauce.

Stir gently until the cream cheese is completely melted and the sauce is smooth and fully incorporated. This may take 10-15 minutes.

Stir in half of the fresh basil just before serving. Garnish with the remaining fresh basil. Serve hot over pasta, rice, or alongside crusty bread.