Cut fish into cubes of about 4 cm, sprinkle with lemon juice and season. Skewer the fish cubes on the rosemary sprigs. Cut vegetables into small cubes, season and spread on the chard leaves in an unperforated container. Place fish skewers on top of the vegetables. Steam for 10 minutes at 80 °C.
Instead of rosemary sprigs, you can use lemongrass as skewers. You can also take any other vegetable for this dish.