Combine yogurt, olive oil, lemon juice, garlic and pepper in a bowl.
Cover and refrigerate for one hour.
Blend yogurt mixture with a whip until smooth.
Dry cucumbers by patting with paper towels.
Add Cucumbers and dill to yogurt mixture.
Salt and pepper to taste.
----------GYROS------------.
Mix lamb and beef in a glass bowl.
Crumb bread into meat mixture.
Add Spices and mix well.
Stir egg into meat mixture Form mixture into 2 large patties and place on a medium hot grill for 5 minutes per side or until the Gyros is cooked through.
Serve sliced gyros on warm pita bread with fresh sliced tomatoes, onions and Tzatziki sauce.