Start the black thread behind the eye and leave it hanging about a third of the shank back from the eye.
Lay one strand of white para-post across the shank at that point, hold it upright, and bind it with a few wraps in front and a few behind so it cannot spin.
Post the wing with thread: a tight wrap while you hold the post, a loose wrap when you let go, and repeat until the post is a couple of millimetres tall. If it is not tall enough you can extend it later.
Bind the grizzly dry fly hackle against the post now, before the body (stripping the barbs off one side of the stem is optional), and take a few wraps up the post to set it.
Take the thread back to the bend and bind in three strands of peacock herl; three rather than two, so if one breaks you still have a body. Break off the butts.
Advance the thread to the eye, then wrap the herl forward in touching turns to just behind the eye. Seat it, whip finish there and snip the thread.
Turn the fly vertical in the vise, hook point up, and restart the thread on the post. Extend the post with a few more wraps if you need more base for the hackle.
Separate the hackle from the post and wind three or four turns down the post, keeping tension on the feather. Zigzag the thread under the barbs to catch it off, then snip the excess.
Whip finish (fingers, if your tool is too big) tight up under the hackle barbs and snip the thread. Trim the post to about the length of a collar hackle and clip any stray barbs hanging below the fly.