I am making this for my fish taco platter, but you could honestly add this to anything. I took this recipe from “The Epicurious Cookbook – More than 250 of our best-loved four-fork recipes” by Tanya Steel. You can make this one week ahead. Cover and refrigerate.
1 red onion (about 12 ounces), halved lengthwise, cut thinly crosswise
5 small jalapeño chilies
2 cups seasoned rice vinegar
3 tablespoons fresh lime juice
1 tablespoon coarse kosher salt
1. Place the onion and jalapeños in a heatproof medium bowl. Mix the vinegar, lime juice, and salt in a small saucepan. Bring just to boil, stirring until salt dissolves. Pour over the onion and jalapeños. Let stand at room temperature at least 1 hour and up to 8 hours.