Soak the Kombu for up to 30 minutes in water to soften.
Place the Shiitake powder in a small dish and add water. Stir with a spoon and leave aside for at least ten minutes.
Place the soybeans in a frying pan and dry roast on medium heat until golden brown (about five minutes). Once there are cracks in the skin and it becomes fragrant, you're good.
To get the dashi out quicker, finely chop the konbu you previously soaked in water. Add the konbu and soybeans to the water used to rehydrate the Shiitake powder and add water so that there's a total of 620ml.
Place (4.) and the rehydrated Shiitake powder in a pot and heat up. Bring to the boil, add flavoring, and stir with a spatula until the coarse sugar melts. Simmer on medium heat for 20 minutes.
Remove from the heat, leave to cool for 10 minutes, and strain. As a rough guide, aim to make about 300ml.
Boil the udon noodles, and eat with the soup from (6.) Add condiments to taste.