Add the pasta to the crockpot. Pour in the diced tomatoes with their juice, cream of chicken soup, milk, shredded chicken and chicken broth. Add the cream cheese block and the minced garlic. Season with salt, pepper, Italian seasoning and garlic powder.
Stir everything together slightly so the pasta is mostly coated with the liquid. Cover and cook on high for 1.5- 2 hours, stirring once or twice during cooking if possible, until the pasta is tender.
Once the pasta is cooked, stir in the Monterey Jack cheese until it’s melted into the dish and fully incorporated. Serve hot and enjoy!