Pour the chicken stock in a slow cooker set to low.
Heat butter in a large non-stick skillet over medium-high heat. Sprinkle one side of each chicken breast evenly with the salt, thyme and pepper. Zest the lemon evenly over the chicken.
Brown the seasoned side of the chicken breasts in the buttered skillet, about 5 - 7 minutes until well browned.
Place the chicken (browned-side up) in the slow cooker with the chicken stock. Cook on low for 6 hours.
Remove the chicken and slice. Add the cream cheese and 1 tablespoon of fresh lemon juice to the chicken stock. Whisk to combine.
Stir in the cooked chicken, artichoke hearts and cooked pasta. Allow to warm back up for about 20 minutes before serving.