Avocado-Tomatillo Sauce (for Taquitos) Recipe

40+ years ago, when my father was in Viet Nam, we lived in his hometown for a year in southern California. There was a drive-in called the Jolly Kone that served taquitos with this runny, hot (heat, not spice) green sauce made with avocados. I've thought about that sauce ever since. I found a recipe a while back (can't remember where and forgot to write it down), but I tried it and it was what I remember...YUMMY!