Combine all purpose flour, active dry yeast, salt, garlic powder, sliced green onions, and 1 ½ cups shredded vegan cheese in a large mixing bowl. Stir to mix all of the ingredients together.
Make a well in the middle of the flour mixture and pour the water into it. Stir until you don't see any more white flour. If the dough is too dry, you can add up to ¼ cup of water. The dough should look shaggy and feel sticky (but not wet) once fully combined.
Cover with plastic wrap (or a towel) and put it in a warm place for 12-18 hours. (I usually put it in the oven with the door shut overnight so it's ready to bake in the morning when I get up.)
Preheat the oven to 450 degrees.
Preheat a cast iron pot with the lid on in the oven for 30 minutes.
While the pot is warming, uncover the dough in the bowl and punch it down. Fold the dough 3-4 times to get rid of any air bubbles. Cover it again and let rise for 30 more minutes.
Carefully, remove the hot pot from the oven. Take off the lid, line the pot with a piece of parchment paper, and sprinkle wheat bran into the bottom of the pot. Scrape the dough out of the bowl and into the hot pot. Sprinkle ¼ cup of shredded cheese on top of the dough.
Put the lid back on and put the pot into the oven. Bake for 45 minutes covered, remove the lid and bake for 5 more minutes or until the crust is a golden brown.
Let the pot sit for a few minutes or until you can handle it safely. Take the lid off and put the wire rack on top of the pot. Hold the rack and flip the pot so the bread is resting on the rack. Let it cool for 1 hour before slicing.