01 -
Using a mandoline slicer, shave the partially frozen beef into thin slices. If unavailable, use a sharp knife ensuring slices are very thin.
02 -
Combine baking soda, vinegar, sugar, garlic salt, onion powder, black pepper, salt, water, and Worcestershire sauce in a bowl. Add the beef slices and let marinate for 20 minutes.
03 -
While beef marinates, dice the onion. Preheat a large griddle over high heat and sauté the onions in 1 tablespoon of vegetable oil until lightly charred, about 1 minute. Remove and set aside.
04 -
Slice each sub roll 3/4 through and place cut side down on the hot griddle. Toast for 15 to 30 seconds until lightly browned. Remove and set aside.
05 -
Drain beef from marinade without rinsing. Heat 3 tablespoons of vegetable oil on the griddle over high heat. Cook beef shavings until foam dissipates and meat is browned and cooked through, approximately 10 minutes.
06 -
Turn off the heat. Divide the cooked beef into six portions directly on the griddle. Top each portion with slices of provolone cheese and allow to sit until cheese melts, 1 to 2 minutes.
07 -
Scoop the beef and melted cheese into each toasted bread roll. Top with the sautéed onions. Serve immediately, optionally with ketchup or horseradish sauce.