Put tomatillos, chili, garlic, and water to cover in medium pot and bring to a boil over medium-high heat. Boil 5 minutes or until tender.
Reserve 1/2 cup cooking liquid, then drain. Remove 2 Tbsp. cooking liquid and combine with Knorr® Chicken flavor Bouillon in small cup. Microwave at HIGH 20 seconds or until very hot. Let Bouillon mixture and remaining cooking water cool to room temperature.
Puree Bouillon mixture, tomatillos, chilis, garlic, onion and cilantro in blender adding as much cooking water as needed to make a smooth salsa.