Beat the butter and sugar and add the egg. Sift the flour with the baking soda and stir it into the rest of the mixture. Mix with a wooden spoon and add the sesame seeds, oats, coconut flakes and the chocolate, broken into pieces.
Lay out a tray with baking paper and preheat the oven to 356°F (180 °C). Shape about 10 biscuits with wet hands and arrange them in the tray, 1 apart.
Bake for 10-15 minutes, remove from the oven and let them cool for 10 minutes before removing them from the tray.