I got the idea from restaurants in Hong Kong which routinely have a little dish of kimchee (Korean spicy cabbage pickle) and another dish of dry roasted peanuts to nibble on while waiting for the meal. Eating them alternately, it has a nice juxtaposition of salty/spicy/sour and peanutty…so then I put achaar and peanutbutter together when I made a sandwich, and voila!