Whisk the flour, dashi, eggs, and salt until just combined. Fold in the cabbage and scallions without overmixing.
Divide the mixture into two portions and keep the pork slices ready beside the skillet.
Cook:
Heat half the oil in a nonstick skillet over medium heat. Add one portion of batter and shape it into a thick round. Lay half the pork over the top.
Cover and cook for 5 to 6 minutes. Flip carefully, cover again, and cook until the cabbage is tender and the pork is browned. Repeat with the remaining batter.
Top and serve:
Drizzle each pancake with okonomiyaki sauce and Japanese mayonnaise. Sprinkle with aonori, bonito flakes, and remaining scallions.
Slice into wedges and serve immediately.
Notes
Mix the cabbage into the batter just before cooking.
Never flatten the pancake while it cooks.
Use vegetarian dashi and mushrooms for a meat-free version.