Combine all the dry ingredients (maize, tapioca, chestnut, chickpea flours, dried yeast and salt) in a bowl and mix with a whisk.
Add the water and cider vinegar and whisk until you have a dough with the consistency of smooth, wet cement.
Grease a small bread tin (I used a 20 cm x 10 cm x 10 cm tin).
Move the dough into the tin. Use a silicone spatula to make this an easy, clean and effective operation. Don't worry about smoothing it out as it will even itself out during the prove.
Cover the tin with a polythene bag to prevent the dough from drying out.
Prove for about an hour in a warm place, aiming for about a 50% increase in volume. Th dough will not hold as much gas as one made with gluten-containing flour.
Preheat the oven to 210°C.
Evenly sprinkle linseed on top of the dough surface.
Bake for 30 minutes until the loaf begins to shrink away from the sides of the tin. Cool on a wire rack.Best eaten fresh. Can be frozen in slices and defrosted as needed.