Mix 2 mugs of self-raising flour, 2 teaspoons of English mustard, and 2 pinches of sea salt in a 26cm non-stick frying pan, then add enough water to make a dough. Mix together with a fork and knead until smooth.
Use a rolling pin to roll out the dough to about the size of a tea towel on a flour-dusted surface, then use your hands to rub the dough with olive oil, spreading it out to the edges.
Roll up the dough lengthways, like a giant cigar, and drizzle with a little more oil, then roll it up like a snail. Flatten it out with a rolling pin, to about the size of the pan.
To cook, dry fry on a medium-high heat for 3 to 4 minutes on each side, or until beautifully golden and crisp. Transfer to a board and smash together to expose the layers.
