Start by adding the chicken thighs to the slow cooker. You don't need to cut it in any way, just put them in whole.
Cut the carrots, celery, and onion into large chunks and add to the slow cooker.
Add salt to taste. Then add in the chicken stock.
Set the slow cooker to high and place on the lid.
When the chicken is tender enough to shred around the 3-3.5 hour mark, remove the chicken and set aside to cool.
While the chicken cools, make the dumplings by combining flour, baking powder, and salt in a mixing bowl.
Cut the butter in o cubes and with your fingers rub the butter into the flour until it looks like a coarse meal.
Add in the buttermilk and mix to fully combine.
Using a disher or ice cream scoop, make equal sized balls of dough and place them onto a sheet pan until you have used up all the dough.
Place the dumplings into the slow cooker.
While they are cooking shred the now cooled chicken with a fork.
The dumplings are done when they are puffy, firm on the outside, and cooked through on the inside. You can carefully stick a toothpick in one to see if it comes out mostly clean. Or check them with an instant read thermometer. They should be around 200 degrees.
The time it takes can vary on how big your dumplings are and how hot your slow cooker gets. Give yourself around 15 to 30 minutes.
When the dumplings are done, carefully add back in the chicken and add in the half and half. Gently stir to combine. Top off with the fresh chopped parsley and the soup is ready to serve.