Pat the fried tofu with a paper towel to remove excess oil and cut it diagonally in half. In a small pot, mix the seasoning ingredients for fried tofu and add the tofu. Heat over medium heat until boiling, then reduce to low heat and simmer for about 5 minutes until the tofu absorbs the flavor.

Slice the green onion diagonally into thin pieces.

Boil a large pot of water and cook the frozen udon noodles according to the package instructions. Drain the noodles well.

In another pot, mix the soup base ingredients and heat over medium heat until boiling. Turn off the heat once it boils.