In a food processor, combine the beans, garlic, 2 tablespoons of the cilantro, 3 ounces of the chiles, lime juice, oil, cumin, paprika, salt, and pepper. Puree until smooth.
Adjust the thickness of the dip by adding up to ½ cup of the bean cooking liquid. Taste and season with more salt or lime juice, if needed.
Scoop the dip into a serving bowl, drizzle with a bit of oil. Garnish with the reserved 1 ounce green chiles, and the remaining tablespoon of cilantro.
The dip keeps well in the refrigerator, so you can make it the day before. It will thicken as it cools, so reserve cooking liquid to stir into it. Also, if making the dip in advance, garnish right before serving.