Chicken Souvlaki With Tzatziki Sauce and Greek Salad Recipe

Name: Chicken Souvlaki With Tzatziki Sauce and Greek Salad Recipe
Ingredients: 5 tablespoons fresh lemon juice (from about 3 lemons); 4 tablespoons red wine vinegar; 4 tablespoons olive oil; 2 tablespoons chopped fresh oregano leaves; 2 teaspoons kosher salt (plus 1/2 teaspoon for sauce and salad); 1/2 teaspoon ground black pepper; 2 pounds skinless boneless chicken breast (cut into 1-inch pieces); 4 cloves garlic (grated, for marinade); 1 clove garlic (grated, for tzatziki sauce); 1 cucumber (peeled, seeded and chopped for tzatziki)