Preheat the oven to 350 ℉. Use a good kitchen scale to weigh dry ingredients if possible.
Combine all dry ingredients in the bowl of a stand mixer.
Lightly beat egg whites and eggs. Add eggs to the bowl along with vinegar and process well until all ingredients come together in a ball.
Gradually add boiling water with mixer running slowly until all liquid is absorbed.
Using an ice cream scoop or spoon, form the rolls and arrange them on a baking sheet with a silicone liner or parchment paper. Leave about 2-inches between rolls.
Place reserved egg yolk in a small bowl and whisk in 1 teaspoon water. Using a pastry brush, coat the tops of each roll with egg wash. Sprinkle 1 teaspoon seasoning over the surface of each roll.
Bake 35-40 minutes until lightly browned.Cool on baking rack for 5 minutes.
Use within 3 days. Refrigerate or freeze the remaining rolls.