Gaijin smashed okonomiyaki recipe (easy and authentic Japanese food)

Today we will be making traditional Kansai-style okonomiyaki, simplified for all you foreigners out there.
Batter ingredients:
-1 cup all-purpose flour
-¼ tsp Diamond Crystal kosher salt
-¼ tsp sugar
-¼ tsp baking powder
-5.6 oz nagaimo/yamaimo (mountain yam) (2-3 inches, 5-8 cm)
-¾ cup dashi (Japanese soup stock) (use standard Awase Dashi, dashi packet or powder, or Vegan Dashi)
-4 large eggs
-½ cup tenkasu/agedama (tempura scraps)
-¼ cup pickled red ginger (beni shoga or kizami beni shoga)
Other ingredients:
-1 head green cabbage (large; 1.6 lb, 740 g)
-½ lb sliced pork belly (or slice your own; you can substitute with shrimp, squid, or mushrooms)
-neutral oil (for cooking the okonomiyaki)
For the quick okonomiyaki sauce
-1½ Tbsp sugar
-2 Tbsp oyster sauce
-¼ cup ketchup
-3½ Tbsp Worcestershire sauce
For the toppings
-okonomiyaki sauce
-Japanese Kewpie mayonnaise
-katsuobushi (dried bonito flakes) (skip for vegetarian)
-green onions/scallions (chopped)
pi-ckled red ginger (beni shoga or kizami beni shoga)