Remove and discard husks from tomatillos; rinse tomatillos. Rinse chili; remove and discard stem. Place tomatillos and chili in a 9-inch square baking pan and broil 4 inches from heat, turning as needed, until browned well on all sides, 12 to 15 minutes total for tomatillos and 6 to 8 minutes for chili. Remove vegetables as done.
In a food processor or blender, whirl tomatillos, chili, garlic, green onions, and lime juice, pulsing just until mixture is coarsely chopped; do not overprocess. Stir in cilantro, then salt and pepper to taste.
Nutritional analysis per tablespoon.