Combine first 4 (liquid) ingredients.
Combine next 3 ingredients together then add to liquid ingredients. Add more flour as needed until you have a smooth ball.
Let rise in a covered bowl, and if possible, set oven to 140º F. and then turn off. Let batter rise in oven for 30 minutes. (If necessary, skip the first rising and put dough in fridge. Not advised, it comes out considerably better if not refrigerated. If you do this, allow to rise again before shaping).
Shape into 2 challot.
Place on a greased cookie sheet and let rise. (Again, if possible, let batter rise in pre-heated 140º F oven for 15 minutes).
Preheat oven to 350° F.
Brush a beaten egg on top and sprinkle with sesame seeds or poppy seeds.
Bake for 30 minutes.