Add the coriander seed to the still-hot pan and roll them around for a couple minutes, or until they, too, smell wonderful. Add the peppercorns and toast for a few more seconds. Grind the hot spices to a fine powder with a mortar and pestle. (The resulting aroma is its own reward.) Add the garlic and salt, working it to a paste. Juice in the lemon, and stir in the olive oil and chopped herb(s). If you prefer to use a spice grinder, let the spices cool a tad, then pulverize them and add to the remainder of the dressing ingredients (mincing the garlic first, of course). Set aside the dressing while you prep the produce.