Turn your crockpot on high or instant pot on low, saute mode.
Chop all produce (to your preferred size) : onion, celery, carrots, fresh thyme, fresh sage, garlic.
Add your butter to the pot until melted, and then add the chopped onion, celery, and carrots. Saute for around 5 minutes until the onions become translucent.
Add the flour, garlic, thyme, and sage to the pot. Stir until flour is fully incorporated. Let cook for another 5 minutes, stirring occasionally to prevent burning.
Pour in the chicken broth/stock, add in the whole chicken breasts, and season with salt and pepper.
If using a crockpot, cover and cook on low for 3 hours or high for 1-2 hours. If using the slow cooker function on an InstantPot, set it to "High" for 3 hours, and make sure you open the vent valve once placing the lid on. If using a pot on the stove, I would set to a low-medium heat and watch to make sure the bottom isn't burning depending on the strength of your oven. Typically 1-2 hours is enough. When there is 1 hour left on your preferred method of cooking, we can start to make the dumplings. In a small bowl, stir together the flour, chopped sage, baking powder, salt, and a pinch of pepper. Add in the milk and stir until just combined.
If using the low function on the crockpot, go ahead and turn the heat up to high.
Remove the chicken breast and shred. Add back into the pot and mix in the heavy cream.
Drop large chunks of dumpling dough into the soup. I usually do about the size of a typical cooking dough ball. Cover the pot (again making sure vent is open on the InstantPot), and cook for the remaining hour.
The dumplings will be puffy and appear soggy on the outside, but once opening one up they should be done in the middle. Serve and season with additional salt and pepper as needed!
