In a large pot, cover chicken with 12 cups of water. Add 2 teaspoon of rubbed sage, 1 teaspoon black pepper, ½ teaspoon onion powder, ½ teaspoon salt and ½ teaspoon of garlic powder. Toss in a bay leaf and stir.
Bring to a boil, then reduce to medium high and cook over a low boil until the chicken is done. Usually this takes around 30 minutes.
The cooking time will vary based on the size and type of chicken. The chicken is done when the center is no longer pink. Do not overcook.
Remove the chicken and let cool. Reserve the cooking liquid. Pour the seasoned broth through a fine-meshed strainer into another pot. Set aside.
In a large bowl, combine the flour, remaining sage, salt, and baking powder.
Add the shortening and bacon fat to the flour. Using a fork or a pastry cutter, work the shortening and fat into the flour mixture until it resembles crumbs.
Add the buttermilk slowly, stirring to combine. Stir and add more buttermilk until a dough forms.
Transfer the dough onto a well floured surface. Sprinkle with more flour. Pat the dough into a flattened shape. Fold the dough in half, sprinkle with flour and repeat.
Repeat this three or four times, flipping and flattening. Add flour as needed to keep the dough from sticking to your hands.
Using a rolling pin, lightly roll the dough into ⅛" thickness. With a pastry or pizza cutter, cut the dumplings into desired sized pieces.
Let the dumplings rest.
Remove the skin and bones from the cooked chicken. Shred or chop the chicken into bite sized pieces. Add the chicken to the reserved strained chicken broth.
Heat the chicken and broth to a boil. Working quickly, drop dumplings in a few at a time, stirring very frequently. Continue dropping dumplings and stirring until they are all in.
Cook and stir for 3 to 5 minutes, then reduce heat to a simmer. Stir frequently and cook for about 30 minutes until the broth has thickened and the dumplings.