Udon is a popular instant or homemade noodle dish in both Korea and Japan. It is a type of thick, wheat-based noodle, usually served in a mildly flavored broth which is seasoned with soy sauce and mirin. Common toppings include tempura, often shrimp or fish cake, or a type of deep-fried tofu pockets seasoned with sugar, mirin, and soy sauce. A thin slice of half moon-shaped fish cake is often added, topped with thinly chopped green onions as well.
Unlike ramyun, udon has mild flavors and it can contain dried seaweeds. So if one doesn't prefer spicy noodles, udon is the perfect substitute dish. However, both types of noodles have delicious broths which are considered to be very refreshing in taste. The flavor of broth and topping may vary from region to region in Asia. This is even noticeable in packaged instant udon noodles, which are often sold in different versions depending on the geography.
Fact: The original udon noodle was 2-3 centimeter in diameter, a flat pancake-shaped noodle added to miso-based soup. It is said to have been imported to Japan from China in the 6th century.