Place steak in freezer bag; combine red wine vinegar, Worcestershire sauce, salad oil and crushed garlic cloves; add to meat. Freeze.
Bundle with: 6 pita breads.
To prepare: thaw steak in marinade. Prepare cucumber sauce. Thaw pita breads and heat. Barbecue or grill under oven broiler until medium rare. Slice steak against the grain in thin strips. Tear thin strip from edge of pita breads; open and stuff with steak and shredded lettuce; add cucumber sauce.
Cucumber sauce: peel and grate cucumber; mix with yogurt. Chill until ready to serve.