Refresh the sourdough by taking 30g of sourdough from the fridge (or freshly made), and combining it with 115g of wholewheat flour and 115g water. Cover and leave to rest at room temperature for about 16 hours.
Toast the sunflower seeds and leave to cool.
in a large bowl, combine 230g of the sourdough (the rest goes back into the fridge for your next bakwith the strong white flour, Kamut flour, peasemeal flour, lupin flour, salt and water.
Knead for 10 minutes, then place back into the bowl, cover and leave to rest at room temperature for one hour.
Knock the dough back, add the sunflower seeds and shape into a loaf to fit into your pre-oiled baking tin.
Place the dough into the tin, cover with a polythene bag to prevent the moisture from evaporating, and leave to rest for several hours until risen.
Preheat the oven to 200 C.
Bake for 50 minutes.
Leave to cool on a wire rack.