Kimchi is fermented cabbage — usually napa cabbage — that forms the foundation of Korean cooking. The fermentation process creates a complex flavour profile combining spice, umami, and acidity in one ingredient. When cooking with kimchi, its pungency intensifies with heat, so balance is key. In dumpling fillings, kimchi adds moisture, so it should be well drained and roughly chopped before mixing with other ingredients. The fermentation liquid itself is a powerful seasoning that can be added separately to sauces and dressings. Look for traditionally fermented kimchi in Asian supermarkets rather than quick-pickled versions, as longer fermentation develops deeper, more complex flavours.