If the mixture is too thin, cook uncovered on high to reduce or thicken with a butter flour roux or cornstarch slurry. Avoid overcooking or undercooking dumplings; they should be light, fluffy, and cooked through. Keep the lid closed while dumplings cook to trap steam for proper texture. Dumplings are done when firm yet soft and a toothpick inserted comes out clean. Store leftovers in the refrigerator up to 3 days. Freeze without dumplings up to 6 months and add fresh dumplings when reheating.