250g Canadian strong white bread flour
ladel (~100ml) rye sourdough starter
75ml water or apple juice
300g finely mashed potatoes
glug of sunflower oil
caraway or onion seeds to decorate
Start in the evening by mixing the 250g strong white bread flour with the 100ml of sourdough starter and 75 ml of liquid. I maintain my starter by feeding it with 50g dark rye and 50ml of water. You may need to adjust the liquid addition to this recipe if the hydration of your starter is not the same. If you've just boiled your potatoes you can use the water from that. I use a 50:50 mix of potato water and apple juice. The sponge mixture will be quite dry so you may need to add a glug of sunflower oil to make it bind. Place the mixing bowl in a plastic bag and leave overnight to ferment. Make your mashed potatoes ready for the morning. The peeled weight needs to be 300g so you need to start with around 350g potatoes. Mash them well so that there are no lumps.
In the morning mix the mashed potatoes with the sponge add 5g of salt and knead for 10 minutes. The dough will be sticky so it could be useful to use a machine with a dough hook but hand mixing is fine. Form into a ball and leave to rise for an hour or two. Remove from the bowl, knock back and place the dough into a baking tin. Decorate with onion or caraway seeds. Leave to prove for another hour.
The dough may not rise much but don't worry, the oven bounce can be huge. Bake in an oven at 250C for 10 minutes with a small jug of water that has just boiled so as to add steam. Now remove the jug of water, lower the temperature to 170C and bake for a further 40 minutes. Enjoy with your lunch!