Start by cleaning the pearl oyster mushrooms gently with a damp cloth to remove any dirt. Slice them into thin strips. Next, chop the medium onion into thin slices.
In a skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced onion and sauté for about 5-7 minutes, or until they are caramelized and golden brown. Stir occasionally to prevent burning.
Once the onions are caramelized, add the sliced oyster mushrooms to the skillet. Cook for another 5-7 minutes until the mushrooms are tender and have released their moisture.
Stir in the Worcestershire sauce, soy sauce (or tamari), balsamic vinegar, garlic powder, onion powder, smoked paprika, oregano, cumin, salt, and black pepper. Mix well and let it cook for an additional 2-3 minutes, allowing the flavors to meld beautifully.
Reduce the heat to low, and layer the vegan provolone cheese over the mushroom mixture. Cover the skillet with a lid and let it sit for a few minutes until the cheese has melted.
Once the cheese is melted, it’s time to assemble your Vegan Philly Cheesesteak! Scoop the cheesy mushroom mixture onto your favorite hoagie rolls or bread of choice. Serve warm and enjoy every bite!