1 envelope instant yeast (or 2 1/4 tsp)
3-3/4 cup bread flour (or all-purpose flour)
3/4 cup warm water (between 105-110 degrees)
2 large eggs, plus 1 egg for glazing
1/2 cup vegetable oil
1-1/2 tsp table salt
1/4 cup sugar
sesame seeds or poppy seeds
In a large bowl, whisk yeast and 3/4 cup flour. Whisk in water until smooth. Let stand 20 minutes, until starting to get puffy.
Whisk 2 eggs, oil, salt, and sugar into yeast mixture. With a wooden spoon, stir in remaining 3 cups flour. Knead dough on a floured surface for about 10 minutes, until smooth.
Place back in bowl; cover with plastic wrap. Let rise 2 hours.
Line 2 baking sheets with parchment. Form 2 challahs, using 12-inch ropes. Place on baking sheets and cover well with plastic wrap. Let rise 1-1/2 hours.
Set up oven--one rack on top, one on bottom. Preheat to 350 degrees. Glaze challah with egg wash (egg with a pinch of salt); sprinkle seeds on top.
Bake for 30 minutes, rotating half-way through.