‘Achar’ is actually a Hindi/Urdu (Hindi: अचार, Urdu: اچار,) word for pickles; see here. It’s also spelt as acha, achaar, or acar in modern Malay spelling. The origins of the word also tell us about the diffusion of foods from South to Southeast Asia.
Here’s the basic barebones acha/achar recipe.
And several pages further on in the notebook, there are more acha notes:
i carrort cut into strips and cucuber cut into strips and mixed vegetables 250gms mushrooms soaked in water add in salt and sugar add in chopped cashews nuts and almond soaked in water and chopped and rasins 250 gm and mayonise and and dark soya sauce and coconut milk 250ml