Begin by cleaning the pearl oyster mushrooms. Gently wipe them with a damp cloth to remove any dirt. Slice them into thin strips. Next, peel and slice the onion into thin rings.
In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced onions and sauté for about 5-7 minutes until they become translucent and slightly caramelized. Remove them from the skillet and set aside.
In the same skillet, add 4 tablespoons of olive oil. Once hot, add the sliced pearl oyster mushrooms. Sauté for about 5 minutes until they begin to brown and soften.
Sprinkle in the onion powder, garlic powder, smoked paprika, oregano, ground cumin, salt, and black pepper. Stir well to coat the mushrooms in the spices. Pour in the Worcestershire sauce, soy sauce, and balsamic vinegar, mixing everything together. Cook for an additional 2-3 minutes, allowing the flavors to meld.
Reduce the heat to low and add the vegan provolone cheese on top of the mushroom mixture. Cover the skillet with a lid to help the cheese melt. Cook for about 2-3 minutes until the cheese is gooey and melted.
Return the sautéed onions to the skillet and stir to combine everything. Serve the mixture on your favorite hoagie rolls or bread. Optionally, you can add some fresh greens or toppings of your choice.
