Preparation

• Season the chicken liberally with salt, including the cavity, and place on a rack on a sheet tray. Refrigerate uncovered 12 to 24 hours before baking.
• Preheat the oven to 275 degrees. Bake the whole chicken on the rack and sheet tray until the breast temperature reaches 165 degrees and the thigh temperature reaches 185 degrees, about 2½ hours. Let cool completely. You can do this step up to 2 days ahead.
• Meanwhile, make the mayo by combining the white vinegar, egg yolk and salt in a large mixing cup. Puree with an immersion blender until well combined, then stream in the avocado oil until thick and emulsified. Set aside.
• Remove the meat from the chicken bones and measure 5 cups for the chicken salad. Reserve any leftover meat for another use. You can also reserve the bones and any drippings to make your own stock.
• Roughly chop the 5 cups chicken and transfer to a medium bowl. Add ¾ cup reserved mayo, the pickles, mustard, lemon juice, red onion, parsley and tarragon. Use your hands to mix the salad, running your fingertips through the mixture, then letting your wrist go limp and whipping the chicken salad with your fingers until well combine. Refrigerate until ready to serve.