Start by bringing your potatoes to a boil in a large pot of salted water. When these are done, you'll want to drain them and let them cool to a temperature you can handle without burning yourself.
While the potatoes cook, chop all the vegetables and measure out any remaining ingredients.
Soup
Add oil to a large soup pot.
Add the celery, carrots, and onions to the pot. Sauté them in the pot until the onions start to turn a light golden brown.
Halfway through sautéing the veggies, stir in the peppercorns.
Once the veggies are about a minute away from being done, add in the pressed or minced garlic. Sauté that with the veggies, stirring constantly, for 1 minute (so the garlic doesn't burn)
Add the chicken broth, vegetable broth, and water to the pot.
Add the raw chicken thighs.
Finally, add in the spices. Stir and bring back to a gentle boil.
Dumplings
While the pot bubbles, peel the warm potatoes.
Mash the cooked potatoes with a fork or potato masher.
Once the potatoes are mashed, add in the egg yolks and seasoning.
Mix well until you have a well-blended dumpling dough.
For softer dumplings, you'll want to spoon small dumpings into the pot of boiling broth. For firmer dumplings, you can roll small dumplings by hand.
Once you drop the last dumpling in, continue to boil for 5 minutes more. All the dumplings should have raising to the top of the pot in this time.
Cool the soup a bit, season with any extra salt you want, and serve.
Video
Notes
Please note that the nutrition data given here is a ballpark figure. Exact data is not possible.