• Gather all the ingredients. Bring a large pot of water to a boil over medium heat, and prepare the rest of the ingredients while it heats.
  

To Prepare the Ingredients

• Slice ½ yellow onion thinly.
  
• Remove the tough core of 2–3 leaves green cabbage and cut the leaves into 1-inch (2.5 cm) squares.
  
• Peel 2 inches carrot and cut into thin slabs, then, julienne them into thin strips 2 inches (5 cm) long.
  
• Discard the tough stems of 2 shiitake mushrooms and slice the mushroom caps.
  
• Cut 2 green onions/scallions into 2-inch (5 cm) pieces. Cut 6 oz sliced pork belly into 1-inch (2.5 cm) pieces.
  
• Blanch 2 servings udon noodles for 30–40 seconds once the water boils, until they just start to loosen. Transfer them to a plate and set aside.

  Nami's Tip: For dry udon noodles, boil them according to the package instructions instead.
  

To Stir-Fry the Yaki Udon

• Preheat a large frying pan over medium heat. Add 1 Tbsp neutral oil and distribute it evenly. Add the pork belly and stir-fry.
  
• Season the pork with ⅛ tsp Diamond Crystal kosher salt and ⅛ tsp freshly ground black pepper. Cook until it‘s no longer pink.
  
• Add the onion slices and stir-fry until tender.
  
• Add the cabbage, carrot, shiitake mushrooms, and green onions. Toss until everything is coated with oil.
  
• Cover with a lid and reduce the heat to medium-low. Steam for 3 minutes, until the vegetables are slightly wilted.
  
• Increase the heat to medium-high. Add the udon noodles to the pan and toss to combine.

  Nami's Tip: Tongs lift the whole tangle at once. Chopsticks and spatulas drag the noodles instead, and udon breaks easily.
  
• Add the Option A seasonings: ½ tsp dashi powder, 2 Tbsp soy sauce, 1 Tbsp sake, and 1 tsp mirin.

  Nami's Tip: Pour the soy sauce against the side of the pan, not over the noodles. The metal there is hotter than the food, so the soy toasts for a second as it lands — that's where the aroma comes from. Let it sizzle, then toss everything together.

  For Option B, add 3 Tbsp mentsuyu (concentrated noodle soup base) and 1 tsp soy sauce instead.

  Nami's Tip: Option B is my go-to whenever there's mentsuyu in the house. One bottle does the work of four seasonings.
  
• Mix it all together. Taste and adjust the seasoning, adding more ground black pepper and salt to your liking.

  Nami's Tip: If any liquid is left in the pan, raise the heat and shake the pan until it cooks off.
  

To Serve

• Transfer the yaki udon to individual plates. Sprinkle 3 Tbsp katsuobushi (dried bonito flakes) over the top and set 2 Tbsp pickled red ginger alongside, if using.
  

To Store

• Store leftovers in an airtight container in the refrigerator for 3–4 days, or in the freezer for 1 month.