To Begin you will need:
-2-5 Potatoes (any type will do, Most fast food companies use the standard Russet, but alot of restaurants are starting to use Kenebec as well)
-Knife or potato cutting device
-Large stove-top pot
-Canola or Corn oil (you can also use peanut as well)
-high range cooking thermometer (a candy thermometer will do)
-paper town or recycled newspaper (for oil dripping)
Start by peeling your potatoes or if you prefer leave the skin on, either way will work just fine.
Pour cooking oil into large pot (do not fill leave about 3-4 inches or more to the top of the pot) then set stove to medium or middle and begin heating oil.
As the oil is heating up take your peeled or unpeeled potatoes and wash them off in the sink for a minute or so, then begin cutting into french fry size pieces (i make about 5 cuts straight through and take out the end pieces then turn the potato 90* lay down and cut 5 or more slits into the potato, then you should have a handful of uncooked fries, take these and put in large bowl and fill with water leave sit for about 5 minutes or so for some of the starch to leave the potatoes, take out then rinse once more then dry as much as you can.
At this point you should check your oil temperature and turn down the stove if it gets up to around 220-250*f (hard to maintain on stove top so move the pot on and off the grill to keep at 250*), submerge fries into oil and be careful as the hot oil may splatter especially if the fries have alot of water on them.(its best to have a splatter guard).
Cook fries at this temperature for about 5 -10 minutes whenever you notice the fries are getting bubbly looking and soft (pull one out with a pair of tongs let cool and squeeze to feel if soft.)
This process is called Blanching and all the fast foods chain fries are supplied to them pre-blanched then frozen.