2 tablespoons light mayonnaise |
4 teaspoons sweet pickle relish |
8 (1.2-ounce) slices whole-grain bread |
1 (4.9-ounce) package roasted skinless, boneless chicken breast, thinly sliced |
4 (0.7-ounce) slices part-skim mozzarella cheese |
2 cups trimmed arugula or spinach |
butter-flavored cooking spray |