Cut the fish into 2 - 3cm thick slices.
Combine the panko and cornflakes in a bowl, then place the plain flour and eggs in separate bowls and season each.
Coat each piece of fish in the flour, then the egg, and finally the cornflake mixture. (For the adults, add fennel seeds and chilli flakes to the cornflake mixture.)
Heat 1cm oil in a frypan over medium-high heat. In batches, cook the fish for 2 minutes per side or until golden and cooked through. Drain.
For the tartare, combine ingredients, season and drizzle with oil. Serve fish fingers with tartare, lemon and green salad.