When we don't have guests I make an easy four-cup-flour recipe that yields two or three small challahs.
2 1/4 tsp. dry active yeast
1/4 c. sugar
1/2 C. oil
3/4 C. lukewarm water
3 3/4 C. flour
Mix yeast with 3/4 c. flour and some of the sugar. Pour water over mixture, mix well and let sit for about 20 minutes until it puffs up. Add oil, eggs, sugar and mix well, then add the remainder of the flour and salt and knead for a few minutes. Add a little more flour if too sticky.
Let dough rise for a couple of hours then form shapes and bake at 350 F for 35-40 minutes.
Sometimes instead of using an egg I sprinkle water over the challah to form a nice crust.