I got this recipe from a website a while ago but sadly I do not remember which one it was in order to give them credit.
1 ¼ pounds tomatillos, (about 10-15) husked and boiled until they change color.
½ cup chopped cilantro
½ cup chopped green onion (about 6 green onions)
1 garlic clove
1-2 whole jalapeno, seeds and ribs removed and roughly chopped
1 teaspoon sea salt
½ cup homemade or low-sodium vegetable broth
Blend together in blender or food processor until fully mixed