A great, allround nymph that was once shown to me by Thomas Lang and Daniel Holm. It has done very well for me anywhere I've fished, and even Paul, I believe, has done well with it in New Zealand. You'll be surprised that even quite large ones fish very well.
The patterns goes like this:
Hook: Curved nymph hook, eg Partridge CZ or CZF or Tiemco 2499SP-BL, size 6-18.
Thread: Tan Uni 8/0.
Rib: Copper or gold mylar flash.
Abdomen: Light olive dubbing.
Thorax: Dark brown dubbing.
Back: Copper or gold flash.
Head/weight: Tungstens bead, lead under thorax if a heavier fly is needed.
Photo by Knud Lovo.