In a mixing bowl, combine mayonnaise and buttermilk. Whisk until well blended.
Add minced garlic and onion to the mixture. Stir until evenly distributed.
Incorporate finely chopped parsley, chives (or green onions), and dill weed into the dressing. Mix thoroughly.
Season the dressing with sea salt and black pepper. Adjust the seasoning according to your taste preferences.
Once all the ingredients are well combined, transfer the Homemade Ranch Dressing to a jar or container with a tight-fitting lid.
Refrigerate the dressing for at least 30 minutes to allow the flavors to meld together.
Shake or stir the dressing before serving to ensure a consistent texture.