For Toasted Spice Rub: Toast cumin seeds, mustard seeds, peppercorns, celery seeds, coriander seeds and allspice in heavy skillet over high heat until fragrant. Remove to small bowl; let cool.
Grind toasted spices to a powder; stir in salt and crushed red pepper.
Combine 6 Tbsp spice rub and Tabasco Chipotle Pepper Sauce; press evenly onto all surfaces of veal shoulder. Wrap in 2 layers of plastic wrap. Refrigerate 6 hours or as long as overnight. Reserve remaining spice rub for Barbecue Sauce.
Mark veal shoulder on grill. Place in roasting pan. Roast in 325°F oven to medium (160°F) doneness, basting halfway through roasting time with 1 cup barbecue sauce.
Per order: Carve veal into thin slices. Serve 5 oz veal on bun topped with 1 Tbsp barbecue sauce. Serve additional sauce on the side, as desired.
Recipe adapted from Chef Waldy Malouf, Beacon Restaurant, New York, New York