Heat the oil in a large skillet over medium heat. Add the mushrooms and cook until beginning to brown, stirring occasionally.
2. Step
Add the onion and cook until translucent. Add the garlic and stir until fragrant. Transfer the mushroom mixture to a large bowl.
3. Step
Add the bread crumbs, oats, parsley, vegetarian Parmesan, oregano, rosemary, thyme, salt, pepper, and cayenne, if using, and stir to combine. Add the eggs and mix well.
4. Step
Cover the bowl and refrigerate for at least 2 hours, or overnight.
5. Step
Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.
6. Step
Use your hands to roll the mushroom mixture into 1-inch (2-cm) balls. Arrange on the preparead baking sheet, spacing evenly.
7. Step
Bake the "meat"balls, flipping halfway, for 20 minutes, or until golden brown.
