Rinse off then rehydrate the dried shiitake in cold water in the fridge for atleast 24 hours to extract a deeper umami. Once they are well soaked, cut off the tough stems. Keep the water the mushrooms soaked in; its a umami-rich mushroom broth.
In a pot on low heat, use sesame oil to gently stir fry your aromatics - garlic, ginger, and shiitake mushrooms.
Add dashi stock, soy sauce, and mirin as well as the water from soaking the shiitake to a gentle boil and cook your udon noodles in the broth to let the rich flavours meld together.
Ladle the udon and broth into bowls. Garnish with chopped green onions, and other toppings such as tempura fried shrimp, nori (seaweed), bonito (fish flakes), and etc.
