Combine 2 cups Greek-style yogurt, ¼ cup fresh lemon juice, 3 tablespoons grated peeled fresh ginger, ½ teaspoon ground red pepper, and 4 minced garlic cloves. Place 7 skinless chicken thighs in each of 2 zip-top plastic bags; divide yogurt mixture evenly between bags. Seal and refrigerate 2 hours. Remove chicken from bags; discard marinade. Sprinkle 1 teaspoon salt over chicken. Arrange chicken on a broiler pan; broil 10 minutes or until done, rotating pan after 5 minutes. Garnish with chopped fresh parsley, if desired.