3 tablespoons vegetable oil
2 tablespoons plain low-fat yogurt
2 tablespoons ketchup
2 tablespoons prepared mustard
1 1/2 teaspoons garlic powder
2 teaspoons paprika
1 1/2 teaspoons ground allspice
1/2 teaspoon black pepper
1/4 teaspoon ground cinnamon
1/4 teaspoon curry powder (optional)
3 pounds skinless, boneless chicken breast halves - cut into bite-size pieces

Dipping Sauce:
1/2 cup mayonnaise
1 cup plain low-fat yogurt
3 cloves garlic, minced
1/4 teaspoon salt