Combine flour, dried thyme or parsley, black pepper, salt, and optional baking powder and baking soda in a large bowl.
Make a well in the center, add whisked eggs, and mix until a firm dough forms, adding milk gradually if too dry.
Bring a salted pot of water to a boil.
Scoop tablespoon-sized amounts of dough into boiling water, dipping your spoon in hot water between scoops to prevent sticking.
Cook dumplings until they rise to the surface, then remove with a slotted spoon and set aside.
In a large pot over medium heat, melt 2 tablespoons of butter.
Add chopped onion with a pinch of salt and cook until soft and golden, about 8 to 10 minutes.
Add remaining butter, cabbage chunks, stock, garlic powder, salt, and pepper; stir to combine.
Cover and simmer until the cabbage becomes tender.
Fold the cooked dumplings gently into the cabbage mixture and toss to blend.
Taste and adjust seasoning with more salt or pepper if needed.
Sprinkle fresh parsley on top before serving.
