Preheat the oven to 450 degrees and line a sheet pan with parchment paper or nonstick foil.
Cut the tomatillos in half through the stem and trim the end of the garlic cloves, leaving their skin intact.
Roast for 15-20 mins or until the tomatillos are softened and lightly browned.
Place the tomatillos (and accumulated juices), garlic, and remaining ingredients in a food processor fitted with a steel blade and process until well blended.
Serve immediately or store in the refrigerator for several days.