Chicken and Grapefruit Souvlaki

Name: Chicken and Grapefruit Souvlaki
Ingredients: 1/2 teaspoon Florida grapefruit zest ; grated; 1/4 cup Florida grapefruit juice; 1/4 cup canola oil; 3 garlic cloves ; minced; 2 teaspoons dried oregano leaves; 1/4 teaspoon each salt and fresh ground pepper; 1 lb boneless skinless chicken breasts ; cut into 1 inch; 1 sweet onion ; cut into chunks; 4 Florida grapefruit wedges ; cut in half crosswise; 1/2 cup 0% plain Greek yogurt; 2 tablespoons Florida grapefruit juice; 1 tablespoon chopped fresh mint; 1 garlic clove ; minced; 1/4 teaspoon salt