This all-purpose condiment—spicy serranos in a sweet-tangy brine—is great on pizza as well as grilled meat and poultry.
In a medium bowl, whisk the vinegar, brown sugar and salt until the sugar and salt have dissolved. Stir in the sliced chiles. Cover with plastic wrap and let stand at room temperature for 2 hours.
The pickled chiles can be refrigerated in the vinegar mixture for up to 2 weeks.