Finely grate the zest of 1 medium lemon into a medium bowl. Juice the lemon into the bowl (about 3 tablespoons). Add ¼ cup buttermilk, ¼ cup tahini, 1 teaspoon garlic powder, 1 teaspoon maple syrup, ½ teaspoon onion powder, ½ teaspoon kosher salt, and a few grinds black pepper. Whisk to combine. If the sauce is too thick, whisk in 1 to 2 tablespoons cold water as needed to thin out.
Finely chop the following herbs into the following amounts and add to the sauce: 2 tablespoons fresh parsley leaves, 1 tablespoon fresh chives, and 1 tablespoon fresh dill fronds. Stir to combine. Taste and season with more salt and pepper as needed.