To make the crepes, sift the flours into a mixing bowl, returning any bran left in the sieve to the flour, and stir in the pinch of salt. Make a well in the centre and add the eggs, gradually add the water, milk and 1 tablespoon of the olive oil and whisk until you have a smooth creamy batter. Cover and leave to stand for 30 minutes.
For the filling, peel the avocados, slice in half, remove the stone and dice the flesh roughly. Toss with the kidney beans and salsa. Season to taste. Mix the soured cream with the chopped coriander and set aside.
To cook the crepes, heat a 20cm non stick frying pan and wipe a little of the remaining olive oil in the pan. Whisk the batter again and using a ladle, swirl a thin layer of the batter over the pan - just enough to give a thin coating. Cook for 2 minutes then flip over with a palette knife and cook the other side for a further 2 minutes. Stack onto a warmed serving dish and keep warm while you cook the remaining batter - you should make 8 crepes. Wipe the pan with a little olive oil before you cook each crepe.
To assemble, fill each crepe with equal amounts of the avocado and bean mixture. Roll up and top with a dollop of the coriander soured cream.