1. Preheat oven to 375F. Put the butter in a large skillet, preferably nonstick, over medium heat. A minute later, add the cabbage and onion. Sprinkle with salt and pepper and cook, stirring occasionally, until the cabbage is quite tender, about 10 minutes. Do not brown. Remove from heat, add the dill, then taste and adjust the seasoning. 2. Meanwhile, hard-cook 3 of the eggs. When they are done, peel and coarsely chop. Add to the cooked cabbage mixture and let cool while you make the batter. 3. Combine the yogurt, mayonnaise, and remaining 3 eggs. Add the baking powder and flour and mix until smooth. Lightly butter a 9x12 baking dish. Spread half the batter over the bottom, then top with the cabbage filling. Smear the remaining batter over the filling, leaving no gaps in the top. 4. Bake for 45 minutes; it will be shiny and golden brown. Let the pie cool for at least 15 minutes before serving.