Tart Vegetable Stew with Fish Balls

This richly flavored vegetable stew with tiny simmered fish balls has a mild chile heat, set off by the tart bite of vinegar. You can use leftover ingredients from the preparation of diebou dien, or you can make and serve the stew on its own as a simple or everyday accompaniment to plain rice.

Josie, the sister of Mariam Seck, who taught me her marvelous version of diebou dien, prepared sauce pikul as a way of teaching me a sim