First, remove the stems and cut the broccoli into bite-sized florets. Wash them thoroughly and drain well. Toss the florets in 2 tablespoons of cake flour to lightly coat each piece—this helps the batter stick better.
In a separate bowl, combine cake flour, potato starch, aonori, salt, and pepper. Add water (or cold carbonated water) and mix until smooth. The batter should be slightly thinner than pancake batter for the perfect crispy texture.
Heat oil to 160–170°C (320–338°F). Dip each broccoli floret into the batter and carefully place in the hot oil. Fry for 1–2 minutes, flip, and cook until golden brown. Remove and place on a wire rack to drain excess oil.
Crispy broccoli tastes best fresh. Serve right away for maximum crunch. Garnish with a little extra aonori or a pinch of sea salt if desired.