Another version of the Mexican pickled vegetables, for canning. Make sure your vinegar is at least 5% acidity (it will say on the label). From The Tasting Table, adapted from a recipe by Kevin West's "Saving the Season".
In a small skillet set over medium-high heat, toast the cumin seeds, stirring often, until golden and fragrant, 1 to 2 minutes. Transfer to a small plate to cool.
Mix the vinegar, water, 1 tablespoon plus 1 teaspoon of the salt, the oregano and crushed peppercorns in a medium saucepan and bring to a boil over high heat. Add the onion and jalapenos and turn off the heat.
Bring a large saucepan of water and the remaining 1 tablespoon of salt to a boil. Add the carrots and simmer until crisp-tender, about 3 minutes. Drain the carrots in a colander and immediately transfer them to the saucepan with the vinegar and onions. Bring the ingredients to a boil, then turn off the heat.
Divide the toasted cumin seeds, garlic cloves and red chiles (if using) among 4 clean pint canning jars. Using a slotted spoon, divide the carrots and onions among the jars. Top with the hot vinegar solution, leaving ½ inch of head space at the top of the jar. Wipe jar rims with a clean, damp cloth and put on lids and rings. Process jars in a boiling water bath for 10 minutes.