Rinse the jalapeno peppers and pat dry. Slice off the stems and cut the peppers into rounds about 1/4-inch thick.

Peel the carrot and cut it into 1/4-inch slices.

Peel the red onion. Use the half called for in the ingredient list and slice that half into 1/4-inch slices; reserve the other half for another use.

Lightly crush the garlic clove (if not already crushed) and lightly crush the black peppercorns.

In a nonreactive saucepan combine 1 cup (250 ml) white vinegar (or unseasoned rice vinegar), 1 cup (250 ml) water, the crushed garlic clove, 2 tablespoons kosher or sea salt, 1 tablespoon sugar, 1/2 teaspoon dried oregano, the 10 lightly crushed black peppercorns, and 1 bay leaf. Heat over medium until the liquid comes to a simmer and the salt and sugar are fully dissolved.

Add the sliced jalapenos, carrot slices, and sliced onion to the simmering brine. Let them cook in the pan for 1 minute, stirring once to submerge.

Remove the pan from the heat, cover it, and let the vegetables steep in the hot brine for 15 minutes.

Ladle the jalapenos, carrots, onions, and brine into clean jars, close the lids, let the jars cool to room temperature, then refrigerate until ready to serve.