In a food processor, add all of the ingredients from chickpeas through black pepper. Pulse until the nuts are broken into very small pieces (but do NOT puree completely). Transfer the mixture to a mixing bowl.
Add 1/2 cup of the gluten flour, and use a fork to stir it into the dry mixture. It's fine if there are small lumps.
Add the other 1 cup of gluten flour and stir again (doing this in batches helps the mixture to retain texture during cooking). Pour the vegetable broth and soy sauce into the bowl and stir until no pockets of dry flour remain.
Line a baking sheet with parchment paper or a Silpat liner, and spray it or lightly grease it with oil. Use a round shaped half tablespoon measure to scoop heaping half tablespoons of the mixture onto the baking sheet. The batter is fairly wet and spongy, so it will probably not be possible to roll the mixture into a ball, which is why I use a round-shaped scoop and let the bottom of the vegan meatballs be flat.
Bake for 20 minutes, or until firm enough to flip over. Flip over all of the meatballs and turn around the baking tray for even cooking, then return to the oven.
Bake for about 15 more minutes, or until the outside is very browned and quite crunchy (the insides of the meatballs should still have a little give to them when you press down).
For cooking the vegan meatballs in a sauce:
Bring your sauce up to a simmer, and then add the meatless meatballs directly to the sauce. These are quite absorbent, so adjust your seasoning accordingly if using a classically salty/reduced sauce (such as teriyaki).
Simmer for just 1-2 minutes for more intense sauces (such as teriyaki), or longer for other sauces like marinara; you can always test one to see if it's absorbed the sauce to your liking! The crunchy outsides will soften when cooked with liquid but the balls will hold their shape.
Unfortunately, there is no way to make this recipe gluten-free, since the gluten flour is so important to the structure and texture.Bob's Red Mill brand (linked in the ingredients list and blog post) is by FAR my most recommended brand of vital wheat gluten flour. In my opinion the combination of price and quality is the best; however, other brands such as Arrowhead Mills should still work for the recipe.The reason I call for raw nuts is that toasted nuts can have an overpowering flavor. If you can only find toasted nuts then I recommend mixing and matching (as opposed to using only 1 type) so that no 1 flavor overpowers the others. In addition to almonds, walnuts, and cashews, sunflower seeds, hemp seeds (mix in after pulsing the rest of the mixture in the blender), and brazil nuts (roughly chop before measuring) can also make nice additions to these vegan meatballs.