I know there are a million and one of these salad recipes out there, but this is a simple one I've served for years on hot summer days when I don't want to heat up the kitchen in the afternoon. The flavor is very good considering the short list of ingredients. I fix it early in the morning so it has time to blend flavors and serve for dinner with a vegi and/or green salad and garlic bread. It is quick, easy and a hit with my family and at potlucks.
Cook macaroni according to package directions, drain, no need to rinse.
While macaroni is cooking, chop onions and celery. In a small bowl mix together mayo, mustard, salt and pepper, set aside.
Put drained, still warm macaroni in large bowl, add tuna, chopped onion and celery and mix together, then add mayo mixture. Mix until all ingredients are well covered with Mayo mixture. Mayo blends in best when macaroni is still warm.
Cover and refrigerate for 6-8 hours to blend flavors. I like to stir it again before serving. Even better the next day. Good for lunch served over lettuce leaves.