Preheat the oven to 400°F, line a baking sheet with parchment paper, and set aside.
Rinse, drain, and cook the rice to the package directions.
While the rice is cooking, add the oats to a high speed blender and blend to a flour consistency.
Pour the oat flour into a medium mixing bowl and set aside.
Clean and dice the fresh mushrooms and onion.
In a medium sized fry pan add the oil, mushrooms, and onion.
Saute for about 10 minutes, or until the onion and mushrooms are starting to brown.
Once they are done, set them aside to cool.
Drain and rinse the black beans and set aside to drain.
In a small dish, blend together all the seasonings, set aside.
Add to the blender the seasonings, half the cooked rice, beans, mushrooms, onion, and blend.
The consistency will be a thick paste and it will easily stick together.
Empty the blended ingredients into the bowl with the oat flour, add the remaining rice, and stir until combined.
Scoop and form the mixture into golf ball sized meatballs and set them on the lined baking sheet.
After filling the baking sheet, place into the oven for 15 minutes, then check and roll the balls around to the other side.
Put the baking sheet back into the oven for another 15 to 25 minutes, checking at 15 minutes for brownness.
Once the meatballs are done, remove from the oven and serve or cool.