Preheat the oven to 180C / 160C Fan / Gas 4.Cut a piece of baking or greaseproof paper to fit a baking tray approx 30 x 20 cm.

Drain the sardines, but keep the liquid you've drained off.Put the sardines in a bowl and roughly mash with a fork.

Add the oatmeal or other flour to the sardines.Add one tablespoon of the reserved liquid and mix together to form a dough, adding more liquid as needed without making the dough too wet.Briefly knead the dough on a surface dusted with oatmeal or flour to finish bringing it together.

Put the cut piece of baking paper on the worksurface and sprinkle with a little more oatmeal or flour.Place the dough on top, sprinkle it and a rolling pin with more oatmeal or flour, then roll out thinly (2-3 mm) into a rough rectangle.Take a knife or pizza wheel and cut the dough into squares or smaller rectangles. Tip: neaten the rectangle first by cutting off the rough edges. These scraps of dough can then be re-rolled and cut into more biscuits with a cookie cutter if liked.

Transfer the baking paper with the biscuits onto a baking tray and put in the oven on a middle shelf.Bake until the biscuits are dry and cooked all the way through (40-50 minutes).- The biscuits at the edge of the tray may cook more quickly: remove and transfer to a wire rack when done and continue cooking the rest.- Turning the biscuits over half way through will help to ensure even cooking.

Leave the cooked biscuits on the wire rack until completely cold then store in an airtight container.Biscuits should stay fresh for at least 2 weeks.Cooked biscuits can also be frozen and fed without defrosting if they have been rolled thinly.