In a bowl, mix active dry yeast, sugar, and warm water. Let it sit for about 5-10 minutes, until the mixture is frothy.

In a larger bowl, whisk together the flour and kosher salt. Add the yeast mixture and vegetable oil to the flour, stirring until a rough dough forms.

Transfer the dough to a floured surface and knead for 7-10 minutes until it's smooth and elastic.

Place the kneaded dough in a greased bowl, cover it with a kitchen towel, and let it rise in a warm place for about 2 hours, or until it has doubled in size.

Brush a cake pan or baking dish with roasted sesame oil. Roll the dough into a 24x9-inch rectangle and brush with more sesame oil. Sprinkle with scallions, salt, pepper, and red pepper flakes.

Starting from one long edge, tightly roll the rectangle into a log. Brush the outside of the log with sesame oil, then slice it into 1.5 to 2-inch pieces.

Arrange the cut pieces cut-side up in the prepared pan. Cover with a towel and let rise for about 30 minutes until slightly puffy.

Preheat your oven to 375°F. Brush the rolls with the egg wash and sprinkle with toasted sesame seeds. Bake for 30-35 minutes or until golden brown.

Allow the rolls to cool briefly before serving. They pull apart beautifully when still warm!