Pepper and Onions: Heat 1 Tbsp of oil in a large saute pan over medium heat. Add pepper and onion, cooking until soft and fragrant, 5 to 7 minutes.
Mushrooms. Meanwhile, shred mushrooms with forks into rough strips. Remove pepper and onions from pan. Heat remaining oil then add mushrooms, soy, Worcestershire, and seasonings. Cook over medium/high heat until mushrooms are soft and moisture has all cooked out, about 10 minutes.
Cheese It: Add pepper and onions back into the pan, mixing into the mushrooms. Shape into 2 or 3 mounds then top each with cheese. Cover and cook until cheese melts, 1 to 2 minutes. Transfer to rolls or buns and serve warm.
*You can make this mushroom cheesesteak vegan but substituting the cheese for a vegan cheese (omit the jalapeno if you're making it for this cheesesteak).