(after grating cucumber squeeze all the juice out of it and keep 1 tsp to stir into yogurt.)Stir together cucumber,sour cream, cucumber juice, dill, garlic and remaining 1/2 tsp. salt.(make this ahead of time and keep it in the refrigerator, as it allows for the flavors to infuse together.)
Cook ground lamb, onion, greek seasoning, pepper, and 1/2 tsp. salt in a large skillet over medium-high heat,stirring often, 7 to 9 minutes or until lamb crumbles and is no longer pink; drain well on paper towels.
Once everything is done, it is time to put it together. Spoon lamb mixture,tomatoes, and lettuce into the pita pocket, then top with cucumber sauce.