This aachar is made with lemons and limes. Nimbu is the Hindi word for a lemon, though they use a different variety that is a little larger than a golf ball and is often green. As a substitute, we are using lemons and limes. Instead of vingear, the fruits are pickled sugar, salt, spices, and their own juices. After sitting in the sun for a few weeks, the peels become soft, and are eaten with the thick liquid.
Use organic fruits, because you are eating the skin! Trader Joe's has 1 pound bags of organic limes and lemons for $1.99, so they don't have to be expensive. I fill up the jars as I cut the lemons and limes, so I know when to stop.
You can use pre-ground spices, but you will get a much better flavor if you toast and grind your own spices. I used cumin seeds, fenugreek seeds, and mustard seeds in about a 5:1:1 ratio. Toast and grind, in a quantity appropriate for the amount of pickles you are making.
Mix with sugar, tumeric, and chili powder in about a 3:1:1 ratio, and and a moderate amount of salt. Combine with the toasted spice mix, going a bit heavier on the sugar mix than the spice mix. There are countless combinations you can use in mixing, and its largely a matter of preference. If you want it extra salty, add more salt. If you prefer it sweet, add more sugar. If you prefer it hotter, add more chili.
Mix layers of fruit with layers of the sugar/spice blend, packing it in well. Once the jar is full almost to the top with dry ingredients, cover with lemon/lime juice, vinegar (if you wish), and oil. Use a neutral oil, or mustard oil if you want a stronger taste.
Cover with a cloth, using a rubber band to keep it in place. Put in the sun (or by the heater, if it is a cool time of year). Stir every two days for two weeks, and then put the lids on. I usually keep it in the sun for another 2-4 weeks with the lid on, giving it a shake every now and then. Between the dehydrating effects of the sugar and salt, the low pH from the citrus juice, and the chemical warfare of the chili powder, no mold will grow.
Serve along with any Indian meal, add to eggs or stir fries, or use as a sauce for chicken wings. This aachar is very strong, so one jar will last a long time. You can use this recipe with other fruits and vegetables, such as green mango, carrots, cauliflower, or a mix. If you like it especially hot, you can also add whole or chopped chilis along with the powder.