One of the most celebrated dishes in Houston was the green sauce at Ninfa’s, a Tex-Mex restaurant chain, now largely gone. (Ninfa Laurenzo died in 2001). I made a batch yesterday to go with the Sous-vide Carnitas , using an adaptation of the recipe in Robb Walsh’s excellent The Tex-Mex Cookbook. This recipe makes a big batch and can be easily halved. With 3 serranos, it definitely has a bit of zip, but is not really hot. (One of my toddler granddaughters seemed to like it in moderate doses on a tortilla chip.)
12 tomatillos, papery husk removed
3 serrano chilies
1-1/2 tsp. salt
¼ cup chopped fresh cilantro
2 cups sour cream
Bring a large saucepan of water to a boil. Add the tomatillos and chilies, reduce to a simmer and cook for 10 minutes until soft. Drain the cooked tomatillos and chilies. Destem the chilies. Add the tomatillos, chilies, and avocado to the bowl of a food processor, and process until smooth. Add the salt and cilantro, and process until well mixed. Add the sour cream and mix in.
Serve with chips or as a salsa for tacos.