Step 1

Bring water to boil in a saucepan. Add the tomatillos, onion, garlic and jalapeño pepper. Lower the heat and simmer for about 15 minutes (until softened). Drain the liquid.

Step 2

In a blender, purée the tomatillos, onion, garlic, jalapeño pepper, vinegar and cilantro. (Make sure to take the vent cap off and cover the hole with a kitchen towel while blending to avoid splatter.)

Step 3

Strain the seeds out of the hot sauce with a fine-mesh strainer. You can use the back of a spoon to push the juices through the strainer.

Step 4

Season with salt, to taste.

Step 5

Store in a bottle in the refrigerator for up to 3 weeks. Shake the bottle before each use.