Finely chop the fresh chives, parsley, and dill (if using fresh). Mince the garlic and very finely mince the shallot or red onion. Measure out the other seasonings so everything is ready.

Combine base ingredients

In a medium bowl, whisk together the mayonnaise and sour cream until smooth and homogenous.

Add buttermilk and acids

Whisk in 3/4 cup of the buttermilk to start, then add the lemon juice and apple cider vinegar. The mixture should be pourable but still creamy; reserve up to 1/4 cup buttermilk to adjust consistency later.

Add herbs, aromatics, and seasonings

Stir in the chopped chives, parsley, dill, minced garlic, and minced shallot. Add the kosher salt, black pepper, granulated sugar, dry mustard (if using), and hot sauce (if using). Mix thoroughly to combine.

Adjust consistency and seasoning

If the dressing is too thick for your use (for drizzling or as a dip), whisk in the reserved buttermilk or up to 2 tablespoons of water, 1 tablespoon at a time, until you reach the desired consistency. Taste and adjust salt, pepper, or lemon juice as needed.

Chill to meld flavors

Transfer the ranch to an airtight container or jar and refrigerate for at least 1 hour (preferably 4 hours or overnight) to allow the flavors to meld and mellow. Stir or shake before serving.

Serve and store

Serve chilled as a dressing, dip, or sauce. Store refrigerated in a sealed container for up to 1 week; give a good stir before each use. If the dressing thickens in the fridge, thin with a little buttermilk or water and whisk to restore desired texture.