Sorry I should have said, plenty of clips on Youtube.
Separate all the muscle groups in the haunch, remove as much sinew and silver skin as possible, cut really thin (5mm or less) strips ACROSS the grain of the meat.
Then soak for 24 hours in your marinade, I use 1/2 bottle Worcester sauce, around the same of Soy sauce, 2 tablespoons brown sugar, then it's down to you, whatever you want, but I like it spicy, so tablespoon of Paprika, Garlic powder, chill flakes and lastly cayenne pepper, not enough to blow your head off but around 2 teaspoons of the pepper.
Make sure every bit is covered and mix it up, and and again a couple of times during the 24 hours.
Spread out the strips on kitchen roll, and press down with more roll, to remove as much liquid as possible.
Lay over racks (I used the wife's cooling racks over tins to stop spillage into oven) making sure they don't touch each other, then into preferably a fan oven at no more than 75c, don't close the oven door, leave a little gap, keep an eye on it, you want to dry it out, not burn it, equally it shouldn't be like leather, you will know when it's time, takes around 1 1/2 - 2 hours, remove, test, and enjoy!
Last tip, don't take it along to a pheasant shoot, at lunchtime my first batch was destroyed by other shooters!
Very popular.
Keeps for around 6 weeks.
Cheers
Richard