Method
Cook the tomatillos and jalapeño in simmering water until softened.
Drain and let cool slightly.
Add the tomatillos, jalapeño, garlic, cilantro, lime juice, and salt to a blender or food processor.
Blend until smooth or slightly chunky.
Taste and adjust the seasoning before serving.
Notes
Use less jalapeño for a milder salsa; refrigerate leftovers in a covered container for up to 3 days.