Add all ingredients except the oil, oregano, and black pepper to a food processor or blender.
Blend on high. With the blender or food processor running, slowly stream in the oil until the dressing is emulsified and thickened. If desired, continue slowly adding more oil for a thicker dressing.
With the machine off, fold in the oregano and black pepper. Taste and adjust seasoning as desired.
Transfer to a quart jar or other airtight container and refrigerate for 2-4 days.
Notes
If your store sells chipotle adobo sauce (just the sauce without the peppers), you can use 2-3 tablespoons of that in place of the peppers and sauce.For a spicier dressing, use more chipotles and/or adobo sauce.Note that this dressing will eventually separate and be hard to shake back together, so I recommend using it within 2-4 days. You can halve the recipe for a smaller batch if desired.Makes 1 quart.