Tie in a tail of long, stiff brown hackle fibers at the bend, Catskill-long. Use a couple of looser wraps first so they do not flare up, then secure. Snip the long butts; the thick body will hide any lump.
Leave the thread near the rear and catch in five or six peacock herls a couple of inches up from the brittle tips. Break or snip the tips off.
Advance the thread to about a third of the way back from the eye. Catch in two hackle tips for the wing, flip them upright, snip the excess behind, and post them with several wraps at the base. Trim any barbs that will not stand.
If you want a semi-spent set, figure-8 a couple of wraps through the wings. Trim any barbs sticking forward so the hackle collar does not look shaggy.
Give the herls a couple of gentle twists together, keeping them clear of the hook point, and wrap a big, chubby body up to the back of the wings. Tie off, pull the butts back and snip.
Catch in the brown rooster hackle behind the wings. Wind three turns behind the wings and two or three in front, using a wrap right in front of the wings to prop them back up.
Pull everything back, form a small head, and whip finish, zig-zagging the thread to avoid trapping fibers. Snip or singe any barbs that get trapped forward.