Deep frying is a cooking method in which food is submerged in hot oil or fat. This is normally performed with a deep fryer or chip pan; industrially, a pressure fryer or vacuum fryer may be used.
Deep frying is classified as a dry cooking method because no water is used. Due to the high temperature involved and the high heat conduction of oil, it cooks food extremely quickly.
+ Fill a pan with oil + Put in the sliced potatoes (with the heat off) + Turn the heat on to high, and cook for 15-20 minutes. + Put french fries on a paper towel, and salt
The french fries will be perfectly cooked in the inside, and brown on the outside.
Here are some links talking about it: http://dinersjournal.blogs.nytimes.com/2010/03/19/an-easy-way-to-make-french-fries/