Large (1 1/2 lb. or so) flank steak
Seasoned Salt or create your own (salt, celery salt, paprika, onion and garlic powder etc.)
Hickory seasoning or "Liquid Smoke"
Trim and slice beef, first into rectangles, then into strips across/diagonal to the grain. Toss with ample seasoning. Lay out on racks with foil underneath to catch the drips. Bake at 140º on convection setting for about 6 hours or until dark, and dry looking. Check from time to time. If you don’t have a convection oven, you may need to adjust the time. If your oven won't go that low, 2-3 hours at 170-200º may be about right.
I keep jerky in the fridge, just to be safe.