When you're in the mood for a sandwich, but not just any old humdrum sandwich will do, this is what you're looking for. A tender hoagie roll cradles roasted pork tenderloin dipped in au jus, then topped with braised broccoli rabe and rich, melty provolone cheese. Along with sweet, roasted corn on the cob, this is the kind of sandwich that makes you happy and sad when you finish it, for you know that you've just experienced something special.
Trim woody ends off broccoli rabe and coarsely chop stems and leaves. Mince garlic. Halve and peel onion. Slice halves into thin strips (julienne). Stem thyme. Shuck corn, rinse, and halve. Rinse pork tenderloin, pat dry, and season with ½ tsp. salt and ¼ tsp. pepper.
Roast Corn and Pork
Place corn on one side of prepared baking sheet. Drizzle with 1 tsp. olive oil and season with a pinch of salt and pepper. Place in oven and roast 10 minutes. Meanwhile, heat 2 tsp. olive oil in a medium pan over medium-high heat. Add pork tenderloin to hot pan and sear on two sides, 6-8 minutes, or until well-browned. After corn roasts 10 minutes, add pork to other side of baking sheet and roast 12-15 minutes, or until corn is slightly charred and pork tenderloin reaches a minimum internal temperature of 145 degrees. Transfer pork to a clean cutting board and let rest 10 minutes. Replace foil on baking sheet.
Steam the Broccoli Rabe
Add broccoli rabe and ¼ cup water to pan used to sear pork (no need to wipe pan clean) and place over medium-high heat. Once water begins steaming, cover and cook 5 minutes, or until tender. Remove broccoli rabe to a plate and discard any remaining water. Season with ¼ tsp. salt and a pinch of pepper. Wipe pan clean.
Make the Au Jus
Heat 2 tsp. olive oil in pan used for broccoli rabe over medium heat. Add garlic, thyme, and onions (reserve a bit for topping sandwich) to hot pan and cook 2 minutes while stirring. Add 2 cups water and chicken base to pan. Bring to a simmer and cook 5 minutes. Season with ¼ tsp. salt and a pinch of pepper. Return broccoli rabe to pan and cook an additional 2 minutes.
Assemble and Bake Sandwich
Slice pork tenderloin into very thin slices, transfer to pan with hot au jus, and stir until well coated in sauce. Place a serving of sliced pork and broccoli rabe on each hoagie, making sure to let any juice drain off first. Add reserved red onion (to taste) to each sandwich and top with provolone slices. Place sandwiches on prepared baking sheet and bake 5-7 minutes, or until cheese is melted.
Plate the Dish
Slice sandwich in half if desired and serve on plate with corn. Serve with au jus on side for dipping.