Season chicken breasts with half the salt and pepper. Heat olive oil in a large skillet over medium-high heat. Cook chicken for 6-7 minutes per side until golden brown and internal temperature reaches 165 degrees Fahrenheit. Remove from heat and let rest for 5 minutes.

While chicken cooks, grate the cucumber and squeeze out excess moisture using a clean kitchen towel or cheesecloth. In a medium bowl, combine Greek yogurt, grated cucumber, minced garlic, chopped dill, and lemon juice. Season with remaining salt and pepper. Mix well until fully combined.

Once chicken has rested, dice it into bite-sized cubes, approximately half-inch pieces. This ensures even coating with the tzatziki sauce.

Add the diced chicken to the bowl with tzatziki sauce. Gently fold together until all chicken pieces are evenly coated with the creamy sauce.

Cover the bowl and refrigerate for at least 30 minutes to allow flavors to meld together. Serve chilled over mixed greens, in pita pockets, or as a wrap filling.