In a small bowl, proof yeast in 1/2 cup warm water mixed with 1 teaspoon of sugar.
While yeast is proofing, mix flour, salt, and remaining 2 tablespoons of sugar in a large bowl.
In a medium bowl, mix remaining 1/4 cup of water, honey, oil, and eggs.
Once yeast has finished proofing, add it to the flour, followed by the wet ingredients.
Mix with a large wooden spoon until dough becomes too thick to stir.
Empty dough onto well-floured surface and knead by hand.
Knead dough until smooth and no longer sticky, adding flour as needed, about 7-10 minutes.
Transfer to an oiled bowl and cover with a damp towel. Let rise for about two hours, or until doubled in size.
Heat oven to 375° F.
Divide dough into three equal parts and then roll each part into a 1-foot log.
Gently flatten each log so that it is about 3 inches wide.
Brush each with toasted sesame oil and then sprinkle with salt, pepper, chili flakes, and scallions.
Roll them up length wise like a jellyroll, pinch the edges to seal, and then braid the logs.
Place the loaf on a parchment-lined baking sheet and then brush with egg wash and sprinkle with sesame seeds and black pepper.
Bake for 20 to 25 minutes until the top is golden brown and the challah is cooked through.