Preheat oven to 400*. Slice the onions. Melt the butter. Combine sour cream and egg til just mixed. Add butter and salt & pepper. Add onions and stir to coat. Divide bread into 6 pieces, and then pat out like pizza dough to make rounds that are about 5" in diameter. Put about 2" apart on ungreased baking sheet. Top with onion mixture and bake for about 25 - 30 minutes until edges of bread are golden brown.
**Note: The original recipe/photo calls for the onions to be sliced into rings but next time I make it I will cut them into strips. I think that will make them more evenly distributed and help for more even baking.