Mix besan and red lentil flour with baking soda, turmeric, ajwain, chilli, amchur and salt.
Combine water and 3 tablespoon oil separately, then stir into the dry mix and knead into a semi-hard dough that holds its shape.
Flatten portions of the dough into long, thin, evenly thick strips.
Arrange on a steamer plate without overlapping. Steam for 10 minutes once the steamer is producing steam.
Remove the fafda from the steamer and allow it to cool.
Preheat the air fryer to 150°C for 5 minutes. Brush the cooled, steamed strips lightly with additional oil. Arrange in the air-fryer basket in one layer without overlapping. Air fry at 150°C for 7–8 minutes and check the crispness; extend gradually if needed.
Cool slightly and serve.