Prep the Blackstone to medium-high heat. Slice onion, green pepper, pepperoncinis and mince the garlic.
Splash the griddle with olive oil and saute onion until translucent. Add garlic to onions and move to the side.
Add 1Tbsp of butter to the onion/garlic mix, and the other Tbsp of butter to the griddle and toast up the hoagie buns.
Once the hoagies buns are toasting, add the green pepper to the onions and combine thoroughly.
Once buns toasted, remove and set aside. Add pepperoncinis to the blend and combine.
Splash more oil on the griddle and add the shaved steak. Cook until browned.
Combine meat with peppers and separate into three piles - roughly the size of the hoagie buns. Add two slices of provolone to each pile and cook until cheese melted.
Add a hoagie bun to each pile - let it set for a minute or two, and flip and make into sandwich. Put the remaining meat/peppers in the bun and eat it up!