Place the tomatillos, garlic, Anaheim chile, onions and jalapeno on a baking sheet. Toss the vegetables with the oil, salt and pepper. Roast the vegetables until the tomatillos turn a dark-green color and the onions golden brown, about 30 minutes.
Let the vegetables cool slightly. Peel the garlic and transfer all the ingredients to a blender. Blend until smooth, about 1 minute. Add the lime juice and sprinkle with more salt and pepper.
The tomatillo sauce can be made 1 day ahead, covered and chilled.