2022年9月21日 · Preheat the oven to 375 degrees F (190 degrees C). Place bread slices in the oven to toast while it preheats, and while you make the tuna salad. In a small bowl, mix together the tuna, mayonnaise, salt, balsamic vinegar, mustard and dill pickle until well blended. Remove bread from the oven, and pile the tuna mixture onto one slice.