In the bowl of a stand mixer, combine warm water and yeast. Whisk briefly, then let it sit for 5 minutes to activate.
Add flour, sugar, salt, and vegetable oil to the bowl.
Using the dough hook attachment, mix on low speed until a rough dough forms; this will take around 8 minutes. If you're kneading manually, expect to work the dough for about 25 minutes.
Lightly grease a large bowl and transfer the dough into it. Cover with a clean kitchen towel and let it rise for about 2 hours, or until it has nearly doubled in size.
Once the dough has risen, turn it out onto a clean work surface.
Cut the dough into 12 equal portions, each weighing roughly 3 ounces.
Take one piece at a time and tuck the edges underneath to shape it into a ball, keeping the top surface smooth.
Place the ball seam-side down on an unfloured surface. Rest your cupped palm over it and roll in small circles, applying gentle but consistent pressure. The dough should tighten and smooth out into a firm ball.
Arrange the dough balls on a baking sheet and cover them with a kitchen towel. Let them rest for 15 minutes.
After resting, use your fingers to poke a hole through the center of each ball. Gently twirl the dough around your fingers until the hole is about 2 inches wide.
Preheat your oven to 425°F (220°C).
Line a fresh baking sheet with parchment paper and dust it evenly with cornmeal, adjusting the amount to your liking.
Fill a large pot with water (about 4-5 cups) over medium-high heat and bring the water to a vigorous boil.
Lower the heat just slightly to maintain a steady boil. Working in batches of 2-3 bagels at a time, drop them into the water. Make sure they have space and don't touch.
Boil each side for 1-2 minutes, or until the bagels puff slightly. (Hint: 1 minute of boiling will produce a light and tender bagel, 2 minutes will produce a chewier and denser bagel.)
Using a slotted spoon, transfer boiled bagels to your cornmeal-dusted baking sheet.
In a small bowl, whisk together one egg white and a splash of water to make an egg wash.
Brush the tops and sides of each bagel with the egg wash, making sure to coat every exposed part to avoid visible egg lines after baking.
Bake for 15-20 minutes, or until the bagels are golden brown. Keep an eye on them, as oven temperatures can vary.
Allow bagels to cool completely on a wire rack before serving. Reheat if desired before enjoying.