Rinse and dry the carrots and radishes well. 

Cut some or all of the carrots and radishes in half lengthwise, if you like. Wash and dry a glass jar with a wide opening (I use an empty jam or coffee jar). 

Cut the lemon in half and squeeze the juice into a small saucepan; reserve the lemon halves. Add the vinegars, sugar, 3 tablespoons salt, masala powder, and coriander seeds. Stir with a wooden spoon and bring the mixture to a boil over high heat, 1–2 minutes. Remove from the heat and let cool for 10 minutes.

Pack the carrots, radishes, and reserved lemon halves into the jar and pour in the brine. The vegetables should be fully submerged. If they are not, add equal parts cider and rice vinegar as needed to cover. 

Cover with the lid and refrigerate for at least 3 hours or up to 3 weeks. The longer the vegetables stand, the stronger the flavor, but I like mine even after just an hour or two of standing. 

Warning: these are addictive. Makes about one 1-pint (500-ml) jar 

Recipe courtesy of The New Kosher (2015).