The main ingredient in miso soup is miso paste, which is a fermented soybean product. Miso comes in various types, including white, yellow, and red, each offering distinct flavors and levels of saltiness. The paste is typically combined with dashi, a Japanese broth made from seaweed and fish, to create the soup's savory base. Additional ingredients often include tofu, green onions, seaweed, and other vegetables, enhancing its nutritional value and taste. Miso soup is a traditional part of Japanese cuisine and is commonly enjoyed for breakfast or as an appetizer.