In a large blender or food processor, combine all of the ingredients and blend until smooth.
Add more milk if needed and increase any of the flavors desired (more cilantro, garlic, lime juice, salt, pepper, jalapeño) to reach your personal preference for the dressing.
Even if you don't like spicy, I wouldn't recommend omitting the jalapeño as it adds a ton of flavor. If you are worried about spice, add a very small amount to start with (make sure to remove all the seeds!)