Cut the Heirloom tomatoes into bite-sized chunks, and add to a large-sized mixing
bowl.
Salt the tomatoes, and allow the tomatoes to sit for roughly ten minutes to drain off
some excess liquid.
In a separate smaller bowl, combine the lemon zest, lemon juice, sliced white
onion, dried oregano, garlic powder, and red pepper flakes.
Allow the onion mixture to sit while the tomatoes drain.
When the tomatoes have sat for roughly ten minutes, drain off the excess liquid
and combine them with the marinated and sliced white onions.
Add the Greek yogurt, mint leaves, basil leaves, chives, dill, and freshly-ground
black pepper, and stir to fully combine.
Taste the mixture, and add more freshly-squeezed lemon juice or salt, if desired.
Serve immediately, or store in the fridge until ready to serve.