Preheat oven to 450°F and position the rack in the middle. In a small bowl, mix rosemary, fennel seeds, salt, and pepper. Rub the pork tenderloin with 2 tablespoons of olive oil and coat it with the rosemary mixture. Place it on one side of a rimmed baking sheet and roast for 10 minutes.

While the pork roasts, toss broccoli rabe with 2 tablespoons of olive oil, garlic, and red pepper flakes in a bowl. In another bowl, toss bell peppers with 1 tablespoon of olive oil.

Remove the sheet pan from the oven, flip the pork, and spread the broccoli rabe and bell peppers around it. Continue roasting for about 20 minutes, or until the pork reaches 145°F and the vegetables are tender.

Transfer the pork to a cutting board, tent it with aluminum foil, and let it rest for 5 minutes. Move the vegetables to a bowl and cover to keep warm. Wipe the sheet pan clean, place split rolls on it, and top with provolone cheese. Bake for about 5 minutes until the bread is lightly toasted and the cheese has melted.

Slice the pork as thinly as possible, then toss it with the remaining 1 tablespoon of olive oil and red wine vinegar. Assemble the sandwiches by layering the pork, broccoli rabe, and bell peppers inside the toasted rolls. Serve warm.