2 pounds top sirloin
¼ cup olive oil
1 teaspoon salt
½ teaspoon pepper
½ teaspoon allspice
Cut beef into approximately 2×2 inch cubes and place in bowl. Cut the onion into quarters and then separate the layers and add to bowl.
In a small bowl whisk together the olive oil, salt, pepper and allspice. Pour over the meat and onion, cover and refrigerate 1-2 hours.
Put the meat onto skewers with a slice of onion in between each piece, careful not to stuff everything together too tightly.
In my experience, top sirloin is best cooked to medium. It seems to be a bit tough if served medium-rare.