In a cast iron skillet, heat 2 tablespoons of olive oil and 2 tablespoons of butter over medium heat. Add 2 sliced Vidalia onions, stirring occasionally. Cook for 25 to 40 minutes until golden brown and softened.

Preheat your grill to medium-high heat, approximately 400°F. Season the strip loin steak generously with salt and pepper. Grill for about 4-5 minutes on one side, then flip and cook for an additional 3-5 minutes.

Allow the steak to rest for 5-7 minutes before slicing thinly.

Slice the French baguette lengthwise down the middle, creating a pocket.

Layer on slices of provolone cheese, then the sliced steak, barbecue sauce, and caramelized onions.

Preheat the oven to 425°F. Place the assembled sandwich open-faced on a cookie sheet and bake for 5-7 minutes until the cheese melts.

Once melted, close the baguette, slice into portions, and serve immediately.