Preparation Cook tomatillos in large pot of boiling water until soft but still whole, about 3 minutes. Drain. Place tomatillos in large bowl and refrigerate until cold, about 1 hour. Place tomatillos in blender. Add remaining ingredients. Blend until smooth. Transfer dip to bowl. Cover with plastic and refrigerate until cold. (Can be prepared 6 hours ahead.)
Preparation Cook tomatillos in large pot of boiling water until soft but still whole, about 3 minutes. Drain. Place tomatillos in large bowl and refrigerate until cold, about 1 hour. Place tomatillos in blender. Add remaining ingredients. Blend until smooth. Transfer dip to bowl. Cover with plastic and refrigerate until cold. (Can be prepared 6 hours ahead.)