In a large skillet, heat a tablespoon of oil over medium heat. Add the sliced white onions and green bell peppers, and sauté until they become tender and slightly caramelized, typically around 10 minutes.
As it cooks, season with 1½ tablespoons of Worcestershire sauce, salt, and pepper to enhance the flavor. Once cooked, remove the pan from the heat and add the onions and peppers back in with the steak.
Spoon the cooked steak mixture evenly onto the rolls, then top the filling with slices of provolone cheese, adding a generous amount to ensure each slider is deliciously cheesy.