Start the black thread about an eye length behind the eye with a jam knot; do not make a thread base yet.
Tie in a piece of pearl Midge Flash on top of the jam knot, wrap back over it about halfway down the bend keeping the thread base smooth, and drape the flash back out of the way.
Select a turkey biot with a stand-up edge and trim the front edge that is not the stand-up edge to narrow it.
Tie the biot in by its tip at the bend, overlapping up to where the thread started, and wrap thread smoothly back up to the start point.
Put a little Zap-A-Gap down the hook shank.
With hackle tweezers, wrap the biot forward with the stand-up edge on the back edge of each turn, spiralling the turns and leaving room between them for the rib; tie it off with a couple of tight turns, clip it, and add a few extra turns to anchor it.
Rib the Midge Flash forward between the biot wraps and trim it.
For the pupa version, dub a fairly prominent ball of black superfine thorax, overlapping the last biot turn, ending right behind the eye; whip finish and trim. (For a larva pattern, stop after the rib and whip finish.)
Other versions
5 more in the app: As tied by East Rosebud Fly & Tackle, As tied by AvidMax, Turkey Biot Midge, as tied by Caddis Fly Angling Shop, As tied by Old Guy outdoors, As tied by Charlie's Fly Box (2).