First, prep the marinade by whisking all marinade ingredients together in a large mixing bowl.
Prepare the chicken by butterflying it open. To do this, cut it in half lengthwise, but not all the way through. Just enough to open it up like a book.
Then slice the chicken into 1 inch thick strips.
Place the chicken in the marinade and cover with saran wrap. Refrigerate 2-12 hours.
When you are ready to cook the chicken, remove it from the fridge and set aside while you prepare the veggies.
Preheat the oven to 425 degrees.
In a bowl combine the diced baby potatoes and trimmed green beans with olive oil, salt and sumac seasoning.
Toss well and pour the mixture onto a sheet pan.
Roast for 15 minutes or until potatoes are tender.
Meanwhile skewer the chicken by sliding the slices onto the skewer in a snake like pattern. I did about 2 strips of chicken per skewer.
Heat a grill pan or cast iron pan over medium high heat and begin the grill the chicken kebabs. I did this in 2 batches.
Grill for 5 minutes on each side, until the internal temperature reaches 165 degrees.
When all kebabs are done, serve them with the sumac roasted vegetables and enjoy