Trim excess fat from meat. Cut into 1 ½ inch cubes. Set aside.
In medium bowl, whisk together olive oil, Worcestershire sauce, garlic, pepper flakes, oregano and lemon juice.
Add in meat, toss to coat.
Pour contents of bowl (meat and marinade) into a large zip lock bag. Refrigerate overnight to allow flavors to mix. At this point, you may also freeze the meat. Before cooking, be sure to thaw the meat thoroughly.
When you are ready to cook…heat your grill or broiler to a medium cooking temperature (325 F).
If using wooden skewers, be sure to soak them for 30 min before using.
Skewer meat onto BBQ skewers and grill until meat is nicely golden brown and cooked through. (You may also wish to add a slice of onion or tomato on the skewers)
Serve with warm pita. Garnish with lemon, tzatziki and sliced onion (tomato and fresh parsley optional)