Place all the ingredients (except the oil) into the bowl of a food processor. Process for a few seconds until everything is combined well and the herbs are all chopped (scrape down the sides half way through).
With the motor running, slowly drizzle the oil in through the feeder tube. Take your time doing this step. It should be a very slow drizzle. Taste and season with extra salt (I often add up to 1/4 tsp more to taste). Season with freshly ground black pepper. Pour the dressing into a jug or container, cover and refrigerate for 2 hours to allow the dressing to thicken slightly and for the flavours to develop.Makes approximately 3 cups. Recipe quantities can be halved.Storage: Keep refrigerated. Will last for 1 week in the fridge.
Note 1: If you prefer a slightly sweeter dressing, you can add up to 2 teaspoons for this recipe. Taste the dressing and adjust. I add 1-2 teaspoons depending on the bitterness of the herbs.