Add all of the ingredients, except the milk, to a medium-sized bowl and whisk together until combined.
Whisk in the milk until the dressing reaches your desired consistency.
Transfer to a glass jar or dish, cover and store in the fridge for at least 30 minutes to let the flavors blend.
Notes
Don't use a blender. You only need a whisk and a bowl to mix together this dressing. Avoid blending it as the fresh herbs will turn the dressing green.
Keep it thick. If you want to keep this dressing thick and use it as a dip, just whisk in 2 tablespoons of milk.
Thin it out. If you prefer a thinner dressing, whisk in 4 tablespoons of milk (or even water) until it reaches your desired consistency. You can add even more if you prefer.