Thanks all.
Well, we had roast potatoes on Christmas Eve and they were very much enjoyed by all. I don't think the potatoes were quite the very 'floury' ones you get here, like Maris Piper or similar but they were great.
Someone else on this thread asked for tips on how to make them, here is my ultimate recipe after trying many different things:
1) Use the most floury potatoes you can - Maris Piper are perfect
2) Peel them, cut them up into reasonable sized pieces. Not too small because they will fall apart into a mush.
3) Boil for 15 minutes or until soft (the roasting in the oven should be to make them crisp, not to make them soft!)
4) Put a tray of your goose fat/duck fat/olive oil into the oven for 10 minutes at 220 degrees
5) drain the potatoes and then shake them up a bit - this damages the outside of the potatoes which makes the surface area bigger and as a result will go more crispy.
6) remove the tray with the hot fat from the oven put the potatoes in. Be careful.
7) Roast the potatoes for 45 to 55 minutes - don't take them out until they're beautifully crispy. If this takes more than 55 minutes be patient!
Your potatoes will be crispy and light and fluffy on the inside.
Enjoy