Make the tzatziki sauce. In a mixing bowl, combine the Greek yogurt, fresh lemon juice, salt, grated garlic, onion powder, white pepper, and black pepper. Add the dried cucumber and stir everything together until well combined.
1 cup plain Greek yogurt, 1 Tablespoon fresh lemon juice, 4 cloves garlic, 2 teaspoons salt, 1 teaspoon onion powder, ¼ teaspoon black pepper, ¼ teaspoon white pepper