Boil water and a sterilize jar.
Cool down 700ml of water.
Grind oat flakes using a blender.
Clean and chop wild garlic.
Place wild garlic and oat flakes in the sterilized jar.
Add boiled and chilled water.
Cover jar with cloth or paper kitchen towel.
Twice a day stir mixture using a chopstick or wooden spoon.
Ferment the oat flakes for another 4 to 5 days.