Combine flour, 1 tablespoon granulated sugar, instant yeast, and salt in the bowl of a stand mixer fitted with the dough hook attachment, then mix to combine

On low speed, add the sourdough discard and water until combined, then increase speed to medium and knead for 4-5 minutes until a smooth ball forms

Grease a large bowl, transfer the dough to the bowl, and cover with plastic wrap, then let the dough rise for 90 minutes or until doubled in size

Turn the dough out onto a smooth surface and divide into 8-10 equal pieces, then roll each piece in your palm to form a smooth ball

Use your thumb to press through the center of each ball, stretching the hole to form your bagel, then cover the bagels with a clean kitchen towel and let rest for 20 minutes

Preheat oven to 425°F, then prepare 2 baking sheets lined with parchment paper or silicone baking mats and bring a pot with 2 quarts of water and 2 tablespoons granulated sugar to boil

Place bagels in the boiling water for 15-30 seconds on each side, ensuring they float, then remove with a slotted spoon and transfer to prepared baking sheets

Whisk together the egg white and 1 tablespoon water, brush each bagel with the egg wash, and sprinkle or dip into desired toppings

Bake for 18-22 minutes or until golden brown, then let cool fully before slicing and serving