Pour the warm water into the bowl of a stand mixer and sprinkle the yeast on top. Stir with a fork, then let stand for 5 minutes.
Add a teaspoon of salt, the sugar, olive oil and whole wheat flour to the yeast. Attach the dough hook to the mixer and beat for a minute until everything is combined. Scrape down the sides of the bowl. Allow this dough to rest for 10 minutes.
Add a cup of all-purpose flour, the oregano and the garlic to the dough. Turn mixer to low speed, and mix for 2-3 minutes, until incorporated. Stop the mixer and scrape down the sides. Sprinkle in the remaining flour.
Knead dough on Low for 8 minutes. Remove dough hook, cover the bowl with a towel and let rise in a warm place for 1 hour. Lightly grease a rimmed baking sheet and sprinkle with cornmeal.
Turn dough onto a lightly floured surface and divide into 12 or 14 pieces, depending on how small you want them to be. Shape them into balls, then roll them to be more oblong. Pinch the ends to make them pointy.
Place bolillos onto the pan and cover loosely with a clean tea towel. Let rise in a warm place for 30 minutes. Meanwhile, preheat oven to 425F. Mix 1/4 cup of warm water and 1/4 teaspoon of salt together.
Place a 9x13 pan on the bottom rack of the oven and pour an inch of water into it. Let it build up some steam for at least 5 minutes while you prepare the buns. Brush the buns gently with the salt water. With a very sharp knife or straight-edged razor, make a lengthwise slash in the top of each bolillo.
Place the pan on the centre rack of the oven. Bake for 15 minutes (or longer, if your bolillos are bigger) without opening the door and letting the steam escape. Cool slightly on the pan and then enjoy warm.
I keep a small razor in a safe place in my kitchen specifically for slashing bread and buns. It's the best tool for the job.