INSTRUCTIONS
1. Process chives, parsley, ¼ cup buttermilk, lemon juice, tarragon, garlic, and anchovies in blender until smooth, about 30 seconds, scraping down sides of blender jar as needed.
2. Transfer 2 tablespoons herb mixture to bowl; add mayonnaise and remaining 1 tablespoon buttermilk and stir to combine. Cover and set aside until ready to serve.
3. Combine salt and remaining herb mixture in 1-gallon zipper-lock bag. Add chicken to bag, press out air, seal bag, and turn to coat chicken in marinade. Refrigerate for at least 2 hours or up to 24 hours.
4. Adjust oven rack to middle position and heat oven to 475 degrees. Line rimmed baking sheet with aluminum foil. Place chicken, skin side up, on prepared sheet (do not brush off marinade that sticks to chicken). Make sure skin is not bunched up on chicken. Roast until breasts register 160 degrees and drumsticks/thighs register 175 degrees, 25 to 30 minutes.
5. Transfer chicken to platter, tent with foil, and let rest for 10 minutes. Serve chicken with sauce.
