- In a deep pan, heat oil over medium heat and toss in onions. Stir fry until softened. Add in sliced beef and stir fry until browned and cooked through. Add soy sauce, sake, mirin, water and brown sugar, bring to a boil for 2 mins.
- To make the broth, turn fire over medium heat and add in water, soy sauce, mirin, sugar and salt. Mix well and allow to heat. Turn down the heat to low and throw in carrots, leeks and mushrooms. Give a quick stir and turn off the heat.
- In a serving bowl, put in udon noodles and ladle in the sukiyaki broth with beef and vegetables. Enjoy this simple one bowl wonder!