In a small bowl combine all of the ingredients for the tzatziki sauce. Mix well and cover and refrigerate until needed.
In a large bowl combine beef, onion, garlic, parsley. Coriander, cumin, salt, and pepper. Mix well. Divide the mixture into 12 balls. Mold each ball around the end of a pointed skewer. Brush the grates of an outdoor grill with olive oil. Heat an outdoor grill to medium-high heat. Add the kebobs and grilled, turning occasionally, until brown all over and cooked through, about 10 minutes.