Peel and then slice the potatoes into chip
shaped pieces (as if you didn't know that
bit already) that are of uniform
thickness (this means that they will cook
evenly and you will not end up with raw chips
and burned chips in the same batch) and
then dry them.
Lower the chips into cool to moderate oil
and cook until soft (squeeze one between
your fingers to check that it is cooked all
of the way through) - they should not
have started to brown on the outside. Take
them out of the oil and warm the oil up until
it just starts to smoke (keep an eye on
it as if it gets much hotter it will catch
fire) and then carefully lower the chips
into it until they are as brown on the
outside as you want. Place on some kitchen
towel to drain.
Mix the flour, salt and baking powder in a
bowl. Add a couple of teaspoons of oil and
then just enough water to make a dough. Roll
this out to a thickness of around a quarter
on an inch and then cut into the shape and
size that you want (they are already the same
thickness so, unless you cut them thinner,
they should all cook at the same rate).
Put the chips into hot oil (no need to
cook them internally first as there is with
potato chips) and leave them until they are
as brown on the outside as you want. Place on
some kitchen towel to drain. Treat these
chips in exactly the same way that you would
potato chips - they will take salt and
vinegar in exactly the same way. No problems
with oil at different temperatures or having
to peel them - flour will keep longer than
potatoes as well.