Vietnamese Grilled Chicken Sandwiches

Name: Vietnamese Grilled Chicken Sandwiches
Ingredients: 2 carrots, peeled and julienned; 1/4 small red onion, thinly sliced; 1/2 cup rice vinegar; 1/2 cup water; 1 Tbs. sugar; 1 tsp. kosher salt; 2 boneless, skinless chicken breast halves, pounded to 1/3-inch thickness; 1 1/2 tsp. Chinese five spice powder; 3 Tbs. vegetable oil; 1 Tbs. fresh lime juice; 2 tsp. soy sauce; 2 tsp. sugar; 1 tsp. fish sauce; 4 deli rolls, split in half lengthwise; 2 radishes, thinly sliced; 1/4 cucumber, peeled and thinly sliced lengthwise; 1/2 jalapeño, thinly sliced crosswise; 1/4 cup fresh cilantro sprigs