In large bowl, combine 1 cup flour, sugar, onion, dill seed, 1 teaspoon salt, baking soda and yeast; mix well.
In small saucepan, heat water, 1 tablespoon butter and cottage cheese until very warm (120 to 130°F.). Add warm liquid and egg to flour mixture; blend at low speed until moistened.
Beat 3 minutes at medium speed. By hand, stir in remaining 1 to 1 2/3 cups flour to form a stiff batter.
Cover loosely with greased plastic wrap and cloth towel. Let rise in warm place until light and doubled in size, 45 to 60 minutes.
Grease 1 1/2 to 2-quart casserole or 10" springform pan. Put a circle of parchment paper in the bottom and grease it. Stir down batter to remove all air bubbles. Turn into greased casserole or springform. Cover; let rise in warm place until light and doubled in size, 30 to 45 minutes.
Preheat oven to 350°F. Bake 30 to 40 minutes or until loaf is deep golden brown and sounds hollow when lightly tapped.
If necessary, cover with foil to prevent over-browning. Remove from casserole dish or baking pan and place on a wire rack. Brush loaf with melted margarine; sprinkle with coarse salt. Cool 15 minutes before removing from pan..