In the bowl of a stand mixer, combine warm water, instant yeast, sugar, and salt. Add 5 1/3 cups of unbleached bread flour and mix until a shaggy dough forms. If the dough feels sticky, add a little extra flour.

Knead the dough for about 10 minutes until it is smooth and elastic. Transfer the dough to a lightly oiled bowl, cover with a damp towel or plastic wrap, and let it rise in a warm place for about 1 hour, or until doubled in size.

Punch down the risen dough and divide it into 8 equal pieces. On a lightly floured surface, roll each piece into a ball. With your thumb, poke a hole through the center and gently stretch the dough to form a bagel shape.

Fill a large pot with water, add sugar, and bring to a boil. Working in batches, gently drop each bagel into the boiling water and boil for 30 seconds on each side. Use a slotted spoon to remove the bagels and let any excess water drain off.

Place the boiled bagels on parchment-lined baking sheets. Immediately sprinkle each bagel with dried onion flakes. If desired, brush the tops lightly with an egg white wash for a shiny finish. Preheat your oven to 400°F and bake the bagels for 20-25 minutes until they are golden brown. Allow the bagels to cool on a wire rack before serving.