In this dish, called ankake udon, the broth is thickened with cornflour and retains its heat for a long time. A perfect lunch for a freezing-cold day, it can be made with ramen noodles rather than udon, if you prefer.
To make the base, place the measured water and all the tare ingredients in a pan and bring to the boil on a medium heat. Remove from the heat when it starts boiling. Stand for 1 minute, then strain. Check the taste and add more salt if required.
Put the noodles in a pan of boiling water and cook for 6–8 minutes or according to packet instructions, until cooked;