Put the egg and spelt flour into a food processor. Add the milk and bicarb, then process for 30 seconds until you get a thick, smooth batter.
Add the spinach and oil, then whizz again for a few seconds. Now keep adding soda water to the batter until you’ll get a mixture resembling single cream.
Lightly grease a pancake pan with oil then heat it over medium heat. Add a ladleful full of batter and let it spread out in the pan. Cook for a minute or so until the surface of the pancake is no longer runny, then flip it over and cook for another few seconds.
Slide the pancake onto a plate, then repeat with the remaining butter. You should get 6-8 pancakes.
Add your chosen filling, then roll them it and cut it in half - alternatively cut the roll into bite-size pieces and serve them as nibbles.