Start the Black thread mid-shank on the 3x long hook and take it back to the rear.
Tie in a long slip of Green duck (or goose) as the tail, pinching the feather and hook together and checking with a couple of medium wraps that it sits on top before locking it down. A small lump here does not matter; the yarn body covers it.
Move the thread forward to a couple of eye-lengths behind the eye and tie in the Silver Mylar tinsel with loose open wraps back down the shank, so the first rib turn comes off the side.
Tie in a full strand of Green wool yarn the same way, binding it back to where the body starts, then bring the thread forward to two or three eye-lengths behind the eye.
Park the tinsel out of the way and wrap the yarn forward in touching turns up to the thread. It looks thick, and that makes the rib stand out. Two or three wraps to secure, then snip.
Wrap the Silver Mylar tinsel forward in evenly spaced turns, not too close so the body still reads green. Take two or three tight wraps, fold the tinsel back, and a couple more over the fold to lock it.
Flip the fly and tie in a medium tuft of Green hackle fibers underneath as the throat, long enough to show. Secure and snip.
Take a Mallard flank tip, fold it over along the stem so the two sides meet in a single tent-shaped wing, and tie it in on top with a pinch wrap. It sits low against the body.
Snip the wing nub, take the thread back to build a big streamer head, then forward behind the eye to bury the stub. Whip finish and coat with UV resin or head cement.