In a bowl, combine the wholemeal spelt flour with all the other ingredients up to and including the salt. Pour in the water, mix with a spoon, but do not knead.
Cover and leave to rise at room temperature for approx. 17 hr.
Heat a casserole dish for approx. 10 mins. in the centre of an oven preheated to 240°C. Place the dough into the casserole dish, make diamond-shaped incisions in the surface, cover, bake for approx. 30 mins, remove the lid, bake for approx. 15 mins. more.