I had my first bite of lime pickle in London. As evidenced by the multitudes of restaurants and street food markets throughout the city, Indian cuisine is heavily intertwined with British food. This is how I happened upon two wedges of pickled lime, sour and spiced, sitting atop a warm buttered crumpet, sharing their bed with a few bits of half-melted sharp cheddar. This was perhaps not a traditional way to enjoy lime pickle, but from that moment on, I make it a point to seek out the condiment whenever I can. Of course, you can buy lime pickle in Indian and British grocery stores and online, but as with most homemade goods, it's just a little more special when you make it yourself.
There are infinite ways to make lime pickle, due to regional variations, ingredient availability, and personal preference. Some cooks use sesame oil and a paste made from crushed red chiles in the pickling liquid, some embrace a heavier blanket of seasoning, turning up amount of chile powder for a fiery red pickle; all are equally stellar in flavor. Here’s one way to do it.
Lime pickle begins with at least some fermented fruit. You can go for the long way: slice 10 limes into 6 wedges each, drop them in a bowl and cover the fruit with 3 tablespoons kosher or coarse sea salt. Transfer the limes into a small mason jar, packing them down. Tightly screw on the lid and then place the jar in a cool, dry place. After 24 hours, dump the mixture out, give it a stir, then recap the jar and let sit in the same place for another 24 hours. You can also buy a large container of preserved lemons and remove the seeds from 2 cups of the fruit, then finely chop and toss it with 8 limes into 6 wedges each. Zest and juice 2 additional limes and incorporate them into the mixture.
Once you have the fermented fruit in hand, in a medium saucepan, heat 2 tablespoons vegetable oil over medium heat, then add 1 tablespoon mustard seeds, 2 teaspoons ground cumin, 1 teaspoon asafoetida, 1 teaspoon dried coriander, ½ teaspoon chili powder, and ½ teaspoon ground turmeric.
After the mustard seeds begin to pop (about 30 seconds), add the limes or preserved lemon and lime mixture, 2 tablespoons water, 1 tablespoon white vinegar, and 1 tablespoon brown sugar. Bring the mixture to a boil, reduce the heat and let simmer for 10 minutes, stirring occasionally.
Take the mixture off the heat and let cool slightly. Spoon lime pickle into small, sterilized jars. Seal the jars and let the mixture sit in the refrigerator at least overnight, or up to 4 days before serving. If properly sealed and sterilized, lime pickle can last in the fridge for several months, if not longer. While you could simply smear the condiment on toast (with or without that British cheddar), lime pickle is also excellent when stirred into a pot of beans, sauteed greens, and rice.