I posted about these years ago because they were so bad, so very very bad, but I have tried again.
I found a discussion about them on Good Housekeeping and it turns out they are pretty damned good.
Cut your chips to the size you like them. Blanch them in salted and boiling water for six to seven minutes or until softened. Rinse and drain them and let them go COLD. Heat your oil to 100 -110 ºC and fry the chips for four or five mins or till they get a light crispy crust. Take them out and let them go COLD again. At this point they can be frozen.
When you need them heat the oil up to 180 ºC or as hot as it will go and flash fry them till they are crisp and golden brown - a couple of mins max. Keep checking during this stage and DO NOT overcook them or let them go brown. Defrost frozen ones for a few mins before cooking.
Worth it IMHO.
The timings will depend on how you like your chips - chunky ones take a bit longer at each stage than French fries types.