Welcome to Nigella

1. Get out your faithful processor, put in the flour, baking powder, salt and oil and pulse until well mixed, then with your motor running VERY slowly pour the water in until it gets sandy, then claggy, then forms a larger damper lump going round.
2. Tip the whole lot (including the blade) out on to a floured surface and whilst its really warm knead this for a few minutes just so it becomes a bit softer. Then bung this in a bowl and put some cling over for ten minutes whilst you have a bit of a clean-down and get out your frying pan or skillet.
3. After ten minutes (or five - doesn't really matter too much) get out your dough and cut it in to eight or nine similar sized pieces. This will make plate sized tortillas.

Ok...this is the important bit. You want:

1. A really hot pan
2. You want to get each piece as THIN as possible...keep rolling and flouring everything
3. You will need to dust off any excess flour before putting in the DRY pan
4. You need to keep the remaining dough under wraps whilst you roll and cook
5. I found it best to roll out one, then put on your awaiting pan for five seconds, it should be hot enough to cause instantish bubbles underneath, then turn for five seconds and put straight into a tea towel and cover awaiting your next one.
6. I find in an airtight zippy kind of bag these last all week and they are quite addictive to make especially when you end up feeling like a very clever mummy!