In a stand mixer bowl, combine 1 1/2 cups flour, yeast, sugar, salt, minced onion and dill seed; mix well. In saucepan or microwave-safe dish, heat yogurt, water and shortening to 120-130°F (shortening does not need to melt). Stir to combine.
Add warm yogurt mixture to flour mixture; blend on low speed for 30 seconds using a paddle attachment. Add egg; beat 3 minutes on medium speed. Gradually mix in enough of the remaining flour to make a stiff batter. Scrape batter from side of bowl.NOTE: For hand mixing: following above steps, mix ingredients in large mixing bowl using a wooden spoon or dough whisk.
Spoon into greased 2-quart casserole. Cover; let rise in warm place until doubled, about one hour.
Preheat oven to 375°F.
Bake for 35 to 40 minutes until golden brown. Brush with butter if desired. Remove from pan; serve warm or cold.