Mix all of the ingredients for the sauce into a bowl. Season with salt and pepper to taste. Adjust any of the ingredients as needed to taste. Set aside.
Preheat the oven broiler on high.
In a bowl mix the beef, Worcestershire sauce, cilantro, cumin, salt, and pepper until fully combined. Place the mixture on a baking sheet and cover with plastic wrap. Using a rolling pin, roll the mixture to about 1/4 inch thick. (To test the flavor cook a small amount in a saute pan)
Remove the plastic wrap and place under the broiler. Cook until nicely browned and somewhat crispy around the edges. (Be careful using the broiler to make sure it doesn't burn or scorch). Drain any excess grease into a jar or used can (not down the sink).
Cut the beef into 1 inch wide by 3 inch long strips to fit the pita.
Warm the pita on both sides in a pan over medium heat for approximately 30 seconds per side.
Layer the pita with beef, lettuce, tomato, onion, sauce, and feta. Fold in half and serve with pickles.