Fermentation, baby! a natural method for preservation, touted currently for helping to maintain a ~ unpleasant word alert!~ gut (yuck, but good).
That and, more importantly, sour is essential. Sour, salty, sweet, bitter and umami are the five categories of taste. Without taste, who would want to eat? Without contrast, who would want to live?
Tuna, onion, pickle, sour cream, celery = Salty, umami, sour/salty, sour, bitter
Pickle, cheddar, sour cream, bread = Salty/sour, umami, sour, bitter
I have made this a few times. If you know me, you have had this birthday cake. Sometimes – shhhh – I make it with Greek yogurt.