Julienne the shiitake mushrooms. Cut the pork into whatever size you prefer (cut them slightly larger as they shrink).
For the soup, you could use A) or B). I don't buy commercial dashi stock, so I made dashi with A). If using B), dilute it if the dashi is concentrated.
Put either A) or B) in a saucepan. If you're eating the noodles in the broth instead of dipping, add 50-100 ml of water (this is for dipping so the flavor is concentrated).
Add Step 1 into the saucepan, and simmer on medium heat. Once it has come to a boil, bring down the heat to low. There's no need to let it boil.
Once the meat has cooked through and the ingredients have softened, it's done.
Story Behind this Recipe
This is my family's udon noodle broth. Even I, who only ever buys the bare minimum when it comes to ingredients, had what I needed to make the soup broth. The meat and shiitake mushrooms soak up the delicious flavors of the broth.
You don't need to measure the ingredients precisely. Adjust the concentration to your liking. You could add aburaage or other ingredients. The ingredients will cook through enough after bringing the saucepan to a boil. It's fine to turn off the heat immediately after bringing it to a boil. I served it with my DIY udon noodles (Recipe ID: 587875)