Preheat grill to medium high.
Rinse chicken breast and trim any excess fat. Pat dry, rub with olive oil and generously salt on each side. Sprinkle with red pepper flakes. Grill 5-7 minutes on each side or until thoroughly cooked depending on thickness. Set aside to cool.
Add Greek yogurt, olive oil, sour cream, lemon juice, garlic, sugar, lemon zest, salt, chives, basil, dill, red pepper flake, and parsley to a medium sized mixing bowl. Stir until combined and taste for seasoning. Cube chicken into bite sized pieces and fold into Greek yogurt mixture until thoroughly coated. Add 1/2 cup small diced cucumber right before serving. Slice the remainder of the cucumber on a bias and spoon chicken salad onto each slice. Garnish with lemon zest, dill, and cracked black pepper. Enjoy!