Add the following to a food processor: Onion, garlic, red wine, lemon juice, olive oil, salt, pepper, allspice, and seven spice. Pulse until there are no chunks remaining.
Pour the marinade over the meat. Cube onion and bell pepper and mix in with the meat mixture. Marinate for at least four hours.
Skewer the meat on metal skewers, alternating with the onions and peppers.
Sprinkle the skewered meat and vegetables with 2 teaspoons of sumac spice. Barbecue over medium-high heat until the meat is cooked to your liking. Medium-rare to medium is how I like it.
Notes
Other steak options include top sirloin and beef tenderloin. Avoid stew meat which is meant to be slow-cooked for a long period.
Serve shish kebabs with hummus, or tahini sauce on the side.
Store leftovers in the refrigerator in an air-tight container for about a week.