This regional speciality calls for a large roast to be grilled (but not smoked) over intensely hot coals while being flipped constantly to avoind burning. The meat comes off the grill well charred, almost black on the exterior but not burned, and rosy pink in the centre, bordering on rare. The meat is sliced thin, piled on kaiser rolls, and top with sliced onions and a horseradish-mayonnaise mixture some locals refer to as "tiger sauce". The final result is tender, smoky and spicy.
In Baltimore, a deli slicer is often used to shave the meat thinly for sandwiches. It's easiest to cut the roast in half lengthwise before slicing it as thinly as possible.
From "The Best of America's Test Kitchen 2010" by Cooks Illustrated
2. Beef: combine all seasonings. Pat meat dry with paper towels and rub evenly over beef. Cover with saran wrap and let stand at room temp for at least 1 hour or refrigerated for up to 24 hours. (If refrigerated, let stand at room temp 1 hour before grilling). Before cooking, unwrap meat and rub with oil.
3. Charcoal grill: open bottom grill vents completely. Light a large chimney started filled with charcoal briquettes (100 briquettes; 6 quarts). When coals are hot, pour in an even layer over 1/2 grill, leaving other 1/2 empty. Set cooking grate in place, cover and heat grill until hot.
4. Gas grill: turn all burtners to high, cover and heat until hot.
5. Clean and oil cooking grate. Place meat on the hotter part of the grill. Cook, (covered if using gas), turning often, until evenly blackened on all sides and the centre of meat is 95-100 degrees (med rare); 30 mins.
6. Transfer meat to a cutting board, tent with foil and let rest 30 mins. Cut roast in 1/2 lengthwise, then slice against the grain as thinly as possible. Divide sliced meat equally among kaisers, top with onion and sauce and serve.