Beef Shish Kebab

If flap meat is thicker than 1/2 inch, butterfly horizontally. Cut meat into 2-inch square pieces. Place meat, oil, onions, parsley stems, salt, cayenne, and black pepper in a large bowl. Toss together using your hands to evenly combine. Cover and marinate in refrigerator at least 24 hours or up to 3 days. 

Open bottom vent of a kettle grill completely. Light charcoal chimney starter heaping full of briquettes. When briquettes are covered with gray ash, pour onto bottom grate; arrange evenly in a 10-inch-wide strip down middle of bottom grate. Do not place top grate on grill. Arrange 2 skewers in an "L" shape, resting on rim of grill, with 1 skewer parallel to coal strip and 1 skewer perpendicular to coals. These will be used as a rack to suspend kebabs.

While charcoal chimney is heating, skewer kebabs. Starting about 3 1/2 inches down from pointed skewer tip, thread about 5 meat pieces (6 to 7 ounces) against the grain onto each of remaining 8 skewers, inserting skewer crosswise into cut side of meat, scraping off onion and parsley pieces and spacing meat pieces about 1/4 inch apart. Discard marinade. Place 1 meat kebab on a cutting board, and cover with plastic wrap. Using smooth side of a meat mallet, pound meat to tenderize and flatten slightly to about 1/3-inch thickness. Total meat length along skewer should be no longer than 10 inches; if needed, push meat pieces together on skewer. Transfer kebab to a rimmed baking sheet. Repeat procedure with remaining kebabs.  

Working in batches if needed, rest pointed ends of skewers on prepared "L"-shaped rack with handles overhanging edge of grill and meat perpendicular to charcoal strip. Grill, uncovered, turning often, until charred in spots and cooked to desired degree of doneness, 4 to 6 minutes for medium-rare (125°F), repositioning kebabs over coals as needed to avoid large flare-ups. If kebabs are browning before reaching desired degree of doneness, rotate kebabs 90 degrees so that they're parallel to charcoal strip.

Using tongs, slide meat off skewers and onto a rice- or lavash-lined platter, if desired. Brush hot kebabs generously with ghee. Serve immediately.