Preheat oven to 400°F and line a baking sheet with parchment paper.
Heat oil in a large skillet over medium-high heat. Add the mushrooms and cook, stirring frequently, for about 10 minutes, or until they’ve browned.
Place the mushrooms, black beans, brown rice, rolled oats, sun-dried tomatoes, bouillon, and spices in a food processor fitted with an s-blade. Pulse until chopped and well mixed. You may need to stop and scrape down the sides of the food processor once or twice. It’s okay if the mixture is a little chunky.
Divide the mixture into 6 equal pieces and shape each one into a patty. If you have one, a ring mold will help shape them, but forming patties by hand is completely fine.
Bake the burgers for 10-12 minutes. Flip them and bake for an addition 8-12 minutes. They should be golden brown and firm.
While the burgers are cooking, mix together the aioli ingredients in a food processor or high-speed blender. If the mixture seems too thick, add a little more water, a tablespoon at a time.
Serve the burgers on whole wheat buns with the Garlic Aioli and your favorite toppings.