Cut the onion in half vertically, then thinly slice it.

Make a slit in the mentaiko and extract the contents.

In a bowl, mix the flour and create a well in the center. Crack the egg into the well and mix. Gradually add water while stirring. Add the onion and mentaiko, then mix lightly to form the batter.

Spread the pizza cheese in a frying pan and heat over medium until melted. Pour the batter over the cheese and cook for about 4 minutes until the cheese becomes crispy. Flip the pancake, drizzle sesame oil around the edges, and cook for another 3 minutes until crispy.

Mix the sauce ingredients (ponzu, sesame oil, sesame seeds, and green onion) in a bowl.