1 cup distilled white vinegar
11⁄2 teaspoons salt
1⁄2 teaspoon sugar
1 large white onion, cut into thin wedges 1 to 2 fresh jalapeņo peppers, thinly sliced

1 cup distilled white vinegar 11 ⁄2 teaspoons salt 1 ⁄2 teaspoon sugar 1 large white onion, cut into thin wedges 1 to 2 fresh jalapeņo peppers, thinly sliced

Place the vinegar, salt, and sugar in a nonreactive bowl and whisk until the salt and sugar dissolve. Stir in the onion and jalapeņos. Press a piece of plastic wrap directly on top of the mixture to keep the onions submerged.
2. Let the onions and jalapeņos pickle at room temperature for 6 to 8 hours, then transfer them to a clean 1-pint jar. Cover the jar, placing a piece of plastic wrap between the mouth of the jar and the lid (to prevent the vinegar from corroding the metal lid). The cebollita can be refrigerated, tightly covered, for several weeks.