What is 'kombu' and how is it used in ramen?

Kombu is a type of edible kelp that is a key ingredient in Japanese cuisine. It's often used to make dashi, which is a fundamental Japanese soup stock that is used in many dishes, including ramen. Kombu has a subtle, savory, and umami-rich flavor that adds a lot of depth to the broth. It's also a good source of minerals, including iodine, calcium, and iron.