Cook the frozen udon noodles according to package instructions, then rinse under cold water to cool.

Drain the saba miso can and flake the fish into small pieces.

Thinly slice the cucumber and separate the shimeji mushrooms into small clusters.

Combine the udon noodles, saba miso, cucumber, and shimeji mushrooms in a large bowl.

Add the men tsuyu, grated ginger, and white sesame seeds to the bowl and mix well.