Boil. Combine tomatillos, onion, garlic, and jalapeños in a large pot. Cover with water by about and inch and bring to a boil.

Simmer. Reduce heat to a simmer and cook until tomatillos are soft, but not falling apart, about 10-15 minutes. Let cool slightly.

Transfer to blender. Using a slotted spoon transfer vegetables to a blender, along with 1/2 cup of the cooking liquid. Add cilantro and 1 teaspoon salt. You may need to do this in batches depending on the size of your blender.

Blend. Blend on high (careful, if the mixture is still hot, hold a few layers of paper towel over the blender instead of the lid. The heat will make the top blow off).

Taste. Once smooth, taste and add more salt if needed. If the mixture is too thick, add a tablespoon or so more of the cooking liquid, keep in mind, the salsa will thicken as it cools, so you want it to be a little runny initially.

Enjoy or store. Transfer to a sealed container and refrigerate until ready to use. Salsa will keep for up to a week in the refrigerator.