There are a number of things that southerners hold dear. One being sweet iced tea, and I guess grits would be one. Biscuits are right up there but they aren't strictly southern anymore. I am thinking the second most revered southern treat (after tea) would have to be the tomato sandwich. I know it is simple but aren't the simple things often the best?
My favorite tomato would be a huge, vine-ripened beefsteak tomato that is at the perfect stage of ripe. You know that glorious color is is almost Coca-cola red. Just a little redder than fire engine red. You know that color! It is best, of course when one slice of tomato fills the whole sandwich.
I prefer whole wheat bread. Growing up it was white bread (usually Sunbeam bread -- remember little Miss Sunbeam?). Then there is the mayonnaise and about this there is an ongoing debate. Some prefer Hellman's or Miracle Whip but in my family it is without a doubt Duke's. In this economy, though, I get the BOGO Free with a coupon which in this case was Hellman's. Then top with plenty of salt and pepper. Top with the second piece of bread and bite into a little piece of heaven!
Now if you don't get home-grown or farmer's market tomatoes it is not going to be good enough.
I have talked to people who don't hold the tomato sandwich in awe and reference as my family members and I do, but I just can't help but believe they aren't truly, authenticly Southern. I might be wrong. I guess you could test out this theory and let me know.