Prep the vegetables for pickling:
Peel the carrots, then cut 1/4 inch slices on a diagonal bias.
Seed the jalapeños, then cut 1/4 inch slices.
Peel the red onion, then cut 1/4 inch slices.
Prep the pickling liquid:
Use a medium saucepan (3 quart or larger). Add the vinegar, water, pickling salt, dried Mexican oregano, and lightly crushed black peppercorns.
Pickle the vegetables:
Add the sliced carrots, jalapeños, and red onion to the pickling liquid.
Cover saucepan with a lid.
Bring to a boil over high heat then turn heat off and leave covered.
Toast the cumin seeds:
Use a small skillet. Add the cumin seeds and toast over medium-high heat. Stir often until the seeds are golden and fragrant, then transfer to a small dish to cool. (1 to 2 minutes)
Prep each jar for pickles and pickling liquid:
Add 1/2 tsp of toasted cumin seeds.
Add 4-6 dried red chilis.
Add 4 cloves of garlic.
Jar the pickles and pickling liquid:
Uncover the saucepan with pickles and pickling solution.
Divide the pickled carrots, jalapeños, and red onion evenly between both jars.
Top each jar off with warm pickling liquid, leaving 1/2 inch of headspace in each jar.
Seal each jar and refrigerate.
Pickles are ready-to-eat after resting overnight. Refrigerate for up to 1 month.