Soak rice in water overnight.
Place rice and water mixture into Thermomix bowl. Add the kefir or buttermilk. (This is your starter) Blend 2 min/speed 9. Add more water if batter is too thick and blend further 1 min/speed 9 (the batter should be very pourable, like a tin of paint, and very smooth).
Place into a Thermoserver bowl and cover. Leave on the bench for 48 hours until there is a faint vinegary smell, and potentially some bubbles.
Stir through the salt flakes.
Line Varoma tray with a piece of baking paper. Oil paper generously using a pastry brush.
Fill bowl to 1L mark with water. Bring to the boil 10 min/Varoma/speed 3.
Stir the batter vigorously with a spatula. Pour first layer of batter into Varoma tray and cook 7 min/Varoma/speed 4.
Repeat the process until all the batter has been cooked. Store in a container with a lid, just covered with water, so they don't stick together. I would generally recommend using these immediately after cooking. It would be better to keep the uncooked batter in the fridge if you are not ready to eat it, then cook fresh as required.
You can slice these pancakes into noodles and use in any noodle dish of your choosing. This site is loaded with such dishes.