Discard the husks and stems from tomatillos. Place tomatillos and jalapeño in a saucepan; cover with water, and bring to a boil. Cook 15 minutes or until tender, and drain.
Combine tomatillos, jalapeño, salt, and garlic in a blender or food processor; process until smooth.
Place a nonstick skillet coated with cooking spray over medium-high heat until hot. Pour tomatillo mixture into pan (mixture will boil vigorously), and cook 2 minutes. Add 1/4 cup water; cook 1 minute or until thoroughly heated. Stir in cilantro.