Japanese Stir-Fried Udon Noodles

INGREDIENTS

• ½ onion (3.5 oz, 100 g for 2 servings)
• 2-3 leaves cabbage (8 oz, 227 g for 2 servings)
• 2 inches carrot (1.8 oz, 50 g for 2 servings)
• 2 shiitake mushrooms (0.7 oz, 20 g for 2 servings)
• 2 green onions/scallions
• 6 oz sliced pork belly (use your choice of meat or seafood; omit for vegetarian/vegan and use tofu, mushrooms, or extra vegetables instead)
• 2 servings udon noodles (6.3 oz/180 g dry udon noodles; 1.1 lb/500 g frozen or parboiled udon noodles)
• 1 Tbsp neutral-flavored oil (vegetable, rice bran, canola, etc.) (for cooking)
• ⅛ tsp kosher salt (Diamond Crystal; use half for table salt) (plus more to taste)
• ⅛ tsp freshly ground black pepper (plus more to taste)

For the Seasonings Option A

• ½ tsp dashi powder (use kombu dashi powder for vegetarian/vegan or skip)
• 2 Tbsp soy sauce
• 1 Tbsp sake
• 1 tsp mirin (or a pinch of sugar)
• For the Seasonings Option B
• 3 Tbsp mentsuyu/tsuyu (concentrated noodle soup base) (the mentsuyu I use is 3-times concentrated; if you use non-concentrated mentsuyu, please add more to achieve the same flavor; here's my Homemade Mentsuyu recipe)
• 1 tsp soy sauce

For the Garnish (Optional)

• 3 Tbsp katsuobushi (dried bonito flakes) (or 1-2 small packages of katsuobushi; skip for vegetarian/vegan)
• 2 Tbsp pickled red ginger (beni shoga or kizami beni shoga)