My take on the Cafe Rio Dressing...

Creamy Citrus and Cilantro Dressing

1/2 bunch cilantro with stems cut off
1/2 Serrano or jalapeno pepper with seeds removed and chopped in pieces (make sure you don't touch your eyes after)
3 tomatillos chopped into fourths (if you don't what these are just ask me)
1/2 t. or so minced garlic
1 envelope Hidden Valley Ranch Dressing (you could also use the Buttermilk packet)
1 c. mayo
1/3-1 c. low fat buttermilk
1 lime juiced

Put first 4 ingredients in a blender or food processor and pulse until very smooth consistency. Then add the rest of ingredients and blend until everything is incorporated. Very easy. Let stand in fridge before serving so it can thicken a little, however this recipe is a little more runny than the real deal. ENJOY!!!