Heat oven to 220C/200C fan/gas 7. Rub
a little oil over each potato and put on
the top shelf of the oven. Bake for 20 mins,
then turn down the oven to 190C/170C fan/
gas 5 and bake for 45 mins-1 hr more
until the skin is crisp and the flesh soft.
Remove from the oven. Make a cross
in the centre of each potato, dollop over
the soured cream and serve.