Cut the ends of the cucumbers off. Peel the carrot.
Cut cucumbers and carrots into strips measuring about 2-inch long and about 1/4 to 1/2-inch thick. Note that the vegetables won't shrink much after salting. Place the strips into a bowl and sprinkle with salt. Toss well with the salt and set aside for 30 minutes.
Make the Rempah
While the vegetables are salting, combine onion, garlic, ginger and macadamia nuts in a food processor and process away until a fine paste is formed. If you don't have a food processor, use a pestle and mortar to pound the ingredients into a paste.
Heat oil in a small pot over medium heat. Add in the onion-garlic paste, chili powder and turmeric powder and stir-fry for 10 to 15 minutes until fragrant, stirring constantly so that the rempah does not burn.
Add in sugar and rice vinegar. Bring the mixture to a boil then remove from heat. Set aside and let cool completely before using.
Finish the Achar
With the help of a cheesecloth or just your hands, squeeze out any excess liquid from the cucumbers and carrots and place them into a clean, dry bowl. Stir in pineapple dices and sesame seeds.
Pour in the Rempah and mix well. Transfer to a clean container, cover and set aside overnight to ferment before sticking it into the refrigerator.
The achar can be kept in the refrigerator for up to 1 month.
NOTES
You can also add cabbage or even long beans into the achar, as long as the total weight of vegetables used is about 700 grams.
To toast the sesame seeds, spread the sesame seeds on a baking sheet. Bake for 10 to 15 minutes at 175C / 350F until golden-brown. Alternatively, dry-toast the sesame seeds on a non-stick frying pan, tossing frequently until golden-brown. Let cool before using.