Prepare the Dumpling Dough
In a medium bowl, whisk together the flour, thyme, pepper, and salt (and leavening agents if using). Create a well in the center and add the whisked eggs. Stir until a stiff dough forms. If it’s too crumbly, add milk one tablespoon at a time until the dough holds together.
Boil the Dumplings
Bring a large pot of salted water to a gentle boil. Using two spoons (or a small cookie scoop), drop tablespoon-sized portions of dough into the water. Tip: Dip the spoons in the hot water first to prevent sticking. Cook until they float to the surface, then remove with a slotted spoon and set aside.
Sauté the Onions and Cabbage
In a large skillet or Dutch oven, melt 2 tablespoons of butter over medium heat. Add the onion and a pinch of salt. Cook for 8–10 minutes until golden brown.
Simmer
Add the remaining 2 tablespoons of butter and the cabbage chunks. Stir in the stock, garlic powder, salt, and pepper. Cover with a lid and simmer for 10–12 minutes, or until the cabbage is tender but not mushy.
Combine and Serve
Gently fold the cooked dumplings into the cabbage mixture. Toss to coat them in the butter and juices. Taste and adjust seasonings. Garnish with fresh parsley and serve warm.