Mix sliced red onion with 2 tablespoons of vinegar and set aside to marinade.
Salt diced cucumber and add to a strainer over a bowl to allow the liquid to drain from them until you're ready to add them to the Tzatziki sauce.
Mix ingredients for Tzatziki and set aside.
If using the salt block to cook salmon, heat the salt block first.
When hot, oil salt block so that the salmon won't stick, while heating, season the salmon.
Mix ingredients for Balsamic Vinaigrette and set aside.
Add lettuce to the bottom of a bowl, top with 1/4 of each of the ingredients, including carrots, red onions, avocado, quinoa, and black eyed peas.
Top with a scoop of Tzatziki and drizzle everything with a bit of balsamic vinaigrette.