On a large griddle or in a large skillet over medium-high heat, toast the rolls, turning occasionally for about 2 minutes, until they are just browned and fragrant. Transfer them to a plate and let them cool slightly. Carefully slice each roll in half lengthwise, making sure not to cut all the way through.

Using the same griddle or skillet over medium heat, heat 1 Tbsp. of oil. Add the bell peppers (if using) and onions. Season with salt and cook, stirring often, until they are caramelized—about 12 to 15 minutes. If using a griddle, push the veggies to one side; if using a skillet, transfer them to another plate.

Pour the remaining 1 Tbsp. of oil onto an empty spot on the griddle (or into the same skillet) and heat over medium-high. Cook the steak, turning occasionally, for about 5 minutes, until it reaches your desired doneness. Season with salt and pepper.

Toss the steak and veggies together to combine (or return the veggies to the skillet and toss to combine). Top the combined ingredients with provolone cheese. Cover and cook until the cheese melts, about 3 minutes.

Divide the cheesesteak mixture among the rolls. Serve immediately while warm and gooey for the best flavor and experience.