Gather all the ingredients. Bring a large pot of water to a boil for the udon noodles. Once boiling, keep it covered on low heat until you‘re ready to heat the noodles.

First, make 2½ cups dashi (Japanese soup stock) of your choice. (To make a quick broth with mentsuyu noodle soup base, see the instructions at the end of the recipe.) Here, I‘ll show you how to make a quick dashi using a dashi packet (you can find it on Amazon). In a medium saucepan, add 2½ cups or 600 ml water and 1 dashi packet. Bring it to a boil over medium heat.

Simmer for 2–3 minutes. Then, squeeze the liquid from the dashi packet and discard the packet.

Add 1½ Tbsp soy sauce, 1 Tbsp mirin, 1 tsp sugar, and ⅛ tsp Diamond Crystal kosher salt and mix it all together. Cover the pot with a lid to prevent evaporation and keep it hot. Remove it from the heat and set aside.

Cut the white part of ½ Tokyo negi (naga negi; long green onion) diagonally into ½-inch (1.3-cm) slices. Set aside.

Thinly slice the leaves and tender stems of 4 sprigs mitsuba (Japanese parsley)(optional).

Cut 1 green onion/scallion into thin slices. Transfer the green onion slices and optional mitsuba to a small plate or bowl for topping the soup later.

Diagonally cut 4 slices narutomaki (fish cakes) (optional). Then, cut 6–8 oz thinly sliced beef (chuck or ribeye) in half to about 1½–2 inches (3.8–5 cm) wide.

Heat the frying pan on medium heat. When it‘s hot, add 1 Tbsp neutral oil and the Tokyo negi.

Sauté the negi until golden brown and tender. Then, add the thinly sliced beef and cook until it‘s no longer pink.

Add 2 tsp sugar and 1 Tbsp soy sauce.

Stir-fry the meat until it is well coated with the seasoning. Remove from the heat.

Cook 2 servings udon noodles in boiling water according to the package instructions. For frozen udon noodles, boil from frozen for 1 minute to reheat. Drain well and rinse quickly with water to remove the excess starch.

Divide the drained udon noodles into individual serving bowls and pour the hot broth to cover.

Place the stir-fried beef, narutomaki, green onions, and mitsuba on top. If you like it spicy, sprinkle shichimi togarashi (Japanese seven spice) on top. Enjoy!

You can keep the stir-fried beef, udon noodles, and broth separately in airtight containers and store them in the refrigerator for up to 3 days.

In a medium saucepan, combine ⅓ cup mentsuyu (concentrated noodle soup base), 2⅓ cups water, and 1 Tbsp mirin and mix well. Bring the mixture to a gentle simmer over medium heat. Cover with a lid and turn off the heat. The udon broth is now ready to use.