Ninfa's Green Sauce

This sauce is popular in many Mexican Restaurants in Houston.
Ninfa's was one of the first restaurants to serve this sauce.  
You get it when you get your salsa and chips before your meal.

3 medium Avocados
3 medium Green Tomatoes
4 fresh Tomatillos 
(find in the specialty fresh produce section of a grocery store)
3 cloves Garlic
2-3 Sprigs Cilantro
1-2 Jalapenos
1 1/2 C. Sour Cream
Salt to Taste

Peel avocados and place them in a blender.
  
In a  medium saucepan, boil tomatoes, tomatillos,
garlic, and jalapenos for 15 minutes.
  
Remove from sauce pan and place all ingredients in a
blender with the avocados.   

Add sour cream and blend until smooth.