Here's a traditional Iranian way to barbecue marinated lamb and tomatoes. If you can't find sumac, try lemon pepper as a substitute.
This was very easy and came out great! I marinated the lamb overnight. I also used little grape tomatoes and alternated lamb and tomato on the skewer. Served with rice and a salad. My boyfriend loved it and I will definitely make it again. - 05 May 2010 (Review from Allrecipes USA and Canada)
I used one onion and chopped instead of grated because I was lazy. Marinated cut up chicken for two hours because that's all the time I had. Thought it tasted great. Served with grilled asparagua and basmati rice - 08 May 2019 (Review from Allrecipes USA and Canada)
I did it under the broiler since it is 10 degrees outside. I also started by broiling mushrooms then added the lamb and then the tomatoes on a foil lined baking sheet. It came out beautifully. The juices were a great bonus. - 18 Mar 2019 (Review from Allrecipes USA and Canada)