Bead the size 12 Daiichi 1190 with a black or black nickel tungsten and start black GSP thread.
Tie in a short red tinsel tag at the bend as the rear hot spot, then a sparse Coq de Leon corzuno medio tail over it.
Tie in the silver wire rib and dub a full, shaggy body of nutria forward to the 65% mark. Nutria is genuinely difficult to dub and only behaves on medium and large flies. Vasies specifically warns against trying it on small hooks.
Rib forward with silver wire in open turns and tie off, then pick the body out hard so the guard hairs stand out in every direction.
Add a few turns of orange thread behind the bead as the front hot spot and whip finish.
Fish it in fast, strong currents where a big general nymph outfishes a precise imitation.