In a 4-quart Dutch oven, cook the diced bacon over medium-low heat for about 5-7 minutes until crispy and golden brown. Use a slotted spoon to remove the bacon and set it aside on a paper towel-lined plate. Reserve about 3 tablespoons of the rendered bacon fat in the pot for added flavor.

In a mixing bowl, whisk together 2 cups of all-purpose flour, 2 teaspoons of baking powder, 1 teaspoon of kosher salt, 1 teaspoon of freshly cracked black pepper, and 2 tablespoons of minced fresh chives until well combined. In a separate bowl, blend ½ cup of sour cream, ¾ cup of whole milk, and the reserved bacon fat until smooth. Gently fold the wet ingredients into the dry mixture until no flour streaks remain, then set aside.

Melt 4 tablespoons of unsalted butter in the same Dutch oven over medium heat. Once melted, add the diced onion, sliced leek, diced carrots, and diced celery, sautéing for 3-4 minutes until the vegetables are softened and fragrant. Stir in 1 teaspoon of dried rubbed sage and 1 teaspoon of dried thyme, cooking for an additional minute.

Sprinkle ¼ cup of all-purpose flour over the sautéed vegetables in the pot, stirring constantly for 2-3 minutes to ensure proper incorporation. Gradually add 6 cups of chicken stock while stirring, ensuring to mix well after each addition until the mixture reaches a gentle simmer and thickens slightly.

Once the soup is simmering, stir in 3 cups of shredded cooked chicken and 1 cup of heavy cream. Bring the mixture back to a simmer, and season with kosher salt and freshly cracked black pepper to taste.

Using a cookie scoop, gently drop spoonfuls of dumpling dough into the simmering soup, ensuring there is enough space between each to allow for expansion. Cover the pot and let the dumplings cook for 15-17 minutes until they look fluffy and step into light golden brown color.

Ladle the creamy chicken and dumpling soup into warm bowls, garnishing with extra chives if desired for a fresh touch. Serve the soup hot, enjoying the delightful mix of flavors and textures.