Place 2.5 cups (~625ml) of water into a pot. Then drop-in 2-3 kelp pieces. Along with a small handful of Katsuobushi flakes. Place it on a high heat and bring to a boil.
Once it is boiling, use a strainer and scoop-out all of the flakes and kelp pieces.
Then add in Hontsuyu Sauce (2 Tablespoons).
Followed by small amount of Soy Sauce (1 teaspoon!)
Then, place in your udon noodles. Let it boil for 2 minutes.
Turn off the heat. Garnish with diced green onions, seasoned tofu pockets and few shakes of shichimi (optional).