Light coals and set grill for direct grilling.

Place cubed sirloin into a medium mixing bowl or container.

Finely chop/mince the yellow onion and add it to the beef. Add salt, sumac, and pepper and mix until all of the meat is coated.

Skewer beef chunks onto skewers. Grill directly over high heat until slightly charred on all sides.

Serve with steamed Basmati rice and grilled tomatoes.