Heat a large skillet over medium-high heat.
Add the butter and melt
Add the diced onion and saute until translucent. Remove onions from the skillet.
Combine the ground beef and Sriracha. Form the ground beef into 2 patties the same size and shape as your hoagie rolls. Generously season the patties on both sides with salt and pepper.
Add the patties to the skillet and cook until well browned on both sides, about 3 minutes per side.
Deglaze skillet with red wine
Using a spatula chop the onions into the patties while breaking up the meat. Cook 2 more minutes.
Top the ground beef mixture evenly with cheese. Cover the skillet until the cheese has melted then transfer the meat to the hoagie rolls.
Top with pepperoncini, lettuce, mayonnaise, mustard, and tomatoes.