I used to par-boil the chips first, as a few have said here, but then my consultant mentioned that instead she sprays the raw chips with frylight, puts them in a microwave bowl and starts them off in the microwave instead for about 5 mins. I find that much quicker.
If you want crunchier chips then the secret is to scuff up the edges after microwaving/boiling and cooling. Put them in a pan with the lid on and give them a good toss about in some frylight.
Another key to better and faster cooking is to use a mesh tray as both sides cook at once then. I've got one that I won in a SW class raffle and I've used it LOADS! It's like a black plastic mesh, square shaped with the edges turned up to create a tray shape. You can apparently get them in Home & Bargains for about £2 or Instore or B&M Bargains for about £3. It's pot luck which stores have them in.
Bon apetit!