Begin by adding the stock, cream of chicken soup, better than bouillon and seasonings to the slow cooker and whisk to combine. Next, add the chicken breast pieces. Cover and cook on the low setting for 4 hours.

After 4 hours, remove the cooked chicken from the slow cooker to a plate and shred using two forks. Set aside.

Finally, add the milk and spaghetti pasta (if you don't have "pot size" cut spaghetti, just break up regular spaghetti pasta into smaller pieces) to the crock pot and give a stir.

Add half of the shredded cheese and top with the shredded chicken. Top everything off with the remaining shredded cheese. Cover and cook for another hour, stirring every few minutes to separate the noodles. Add more milk if needed to keep everything moist with a creamy consistency.

Serve hot. Garnish with fresh chives or scallions if desired.