The phrase "to pickle the carrots" means to preserve or store the carrots in a special liquid called pickle, which adds flavor and extends their shelf life. Full definition
Add the other part of the French roll and serve immediately with pickled carrots and a spicy salsa. (mexicoinmykitchen.com)
* To make pickled carrots, whisk together 1 cup water, 1/2 cup apple cider vinegar, 3 teaspoons salt and 2 teaspoons sugar until salt and sugar are dissolved. (latortillafactory.com)
Not only were they much hotter than I was expecting but contained pieces of pickled carrots and onions too. (tinandthyme.uk)