In a medium bowl, mix together all of the dry ingredients (dried dill, garlic powder, dried parsley, onion powder, onion flakes, dried chives, ground black pepper, and fine sea salt).
In a separate bowl, whisk together the mayonnaise and buttermilk until smooth.
Add the dry ingredients to the wet ingredients and mix until all of the spices are evenly distributed.
Cover and refrigerate overnight for best results.
When ready to serve, whisk the dressing one more time and transfer it to a serving bowl or jar. If desired, garnish with fresh herbs such as parsley or chives.