Stir together the flax seeds and water and set aside to thicken.
Stir together the remaining ingredients until combined, then stir in the thickened flax seed mixture.
Shape into 8 balls and press to flatten.
Heat the oil in a frying pan and cook the patties for about 5 minutes on both sides until golden brown.
Drain on absorbent kitchen paper.
Serve with kohlrabi sauce and herbs.