Add the garlic to the blender, and chop in blender. Add the rest of the dressing ingredients and blend until smooth, scraping down the sides intermittently to make sure it is well combined.
Notes
If you don't have buttermilk, you can pour 1/2 a tablespoon of white vinegar into a glass measuring cup and then fill the cup to the 1/2 cup mark. Let it sit for 5 minutes.