Tangy pasilla shrimp

Pull the stems off the pasilla chiles and cut into rings; slice half a small red onion.

Warm olive oil in a large skillet and toast the chile rings, stirring, about a minute until they change color and release their aroma.

Add the onion and toss, then the balsamic vinegar, a sprinkling of salt, about a tablespoon of sugar and a third of a cup of water; simmer about a minute.

Peel the shrimp and slice down the back to remove the vein.

Add the shrimp and stir until pink; slide into a serving dish, scatter cilantro leaves over, and serve cold, at room temperature or warm.