Line the base of a 1.5 Litre loaf tin with parchment paper, grease the sides with sunflower oil and dust with flour. Set to one side.
Begin with the seeds and oats. Place them into a bowl and cover with 100ml boiling water. Leave to absorb the water.
Meanwhile heat the butter (or oil) in a saucepan on low to melt, then add the kefir, heat to 37°C. Remove from the heat. Pour the contents of the saucepan into a bowl of a free standing mixer.
Now cover the dough and prove for 30-45 minutes, depending on the temperature of your kitchen. It will almost double in size.
Place on the lower part of the oven. Reduce the temperature to 175°C as soon as you place the tin in the oven. Bake for about 1 hour.
