Preheat oven to 350°F. Place the meat in the freezer for 60-90 minutes to make it easier to slice thin.
Slice each bell pepper in half top to bottom through stem. Remove seeds and membranes. Place in a rectangle 9x13" casserole dish that has been sprayed with cooking spray or olive oil. Bake for 25 minutes uncovered.
Lay the rib eye steak flat on a cutting board. Using a sharp knife, thinly slice the meat from one end, down length of the steak (See video). Set aside.
Heat oil in a large skillet over medium-high heat. Add the onions and season with half of the kosher salt. Cook until soft and starting to brown and caramelize, 5 minutes. Remove onions and set aside.
Add steak to hot skillet, this will cook quickly and sear edges. Add onions and season with remaining kosher salt, black pepper and Worcestershire sauce. Cook, stirring occasionally, 3 minutes.
Add provolone cheese to bottom of each baked pepper and top with steak and onion mixture. Top with another piece of provolone and broil until golden and bubbling, 3 minutes.
Notes
A substitute could be sirloin tip roast, sliced thin. Place the meat in the freezer for 60-90 minutes to make it easier to slice thin.
Cheez Whiz is also known to be a substitution for the provolone, but I do not recommend it for the top, maybe just inside with the caramelized meat and onions.