1/4 Cup Extra Virgin Olive Oil
2 tsp Oregano
2 garlic cloves, minced
1 Tbsp Ground Cumin
1 tsp Ground Coriander
1/4 tsp Cayenne
2 pounds sirloin flap steak or flatiron steak, cut into 1 1/2-inch pieces
12 (12-in) skewers, soaked in water 30 min if wooden
Stir together olive oil, oregano, garlic, spices, and 1 tsp salt in a bowl, then toss with beef chunks. Marinate beef, chilled, at least 2 hrs (and up to 8 hrs).
Prepare grill for direct-heat cooking over medium-hot charcoal (high heat for gas). Thread about 4 pieces of marinated beef onto each skewer, leaving small spaces between the pieces, then transfer kebabs to a tray.
Oil grill rack, then grill beef skewers on heated grill, (cover the grill if you are using a gas grill). Continue to cook until beef is browned but still pink inside, turning every 4 to 5 min.