Cut a 1/2-inch slice off top of each roll; set tops aside. Hollow out center of rolls, leaving 1/2-inch-thick shells. Reserve excess bread for another use.
Combine tuna and remaining ingredients, tossing gently. Spoon tuna mixture evenly into shells; cover with tops. Transfer sandwiches to a baking sheet. Bake at 400° for 15 minutes or until thoroughly heated; serve warm.