You will find some version of this condiment, a sharp, bright finisher that is like a squeeze of lime juice on steroids, on nearly every table in the Philippines. It perks up everything here, and frankly, just about anything you grill.
- 1 oz. red Thai chiles (about 20)
- 1 scallion, white and pale green parts only
- 1½ cups cane vinegar (such as Datu Puti) or unseasoned rice vinegar
- ½ small red onion, finely chopped
Blend chiles, garlic, scallion, vinegar, salt, peppercorns, and sugar in a blender until finely chopped. Transfer to a nonreactive bowl and mix in onion.
Do Ahead: Vinegar can be made 2 months ahead. Cover and chill.