In a buttered pie dish, roll out the shortcrust pastry and prick it with a fork or knife. Bake at 180° (gas mark 6) for 10 to 15 minutes.
Meanwhile, cut the fennel into thin strips and sauté in an oiled frying pan. Add the vanilla. Flambé the fennel with PASTIS DE L'ILE DE RE. Add a glass of water and season with fleur de sel and pepper. Leave to stew for 20 minutes.
Once cooled, add the lemon juice. Place the mixture on the puff pastry. Add the red mullet fillets on top. Sprinkle with chilli (don't be too heavy-handed!), dill and a drizzle of olive oil.
Bake for 10 to 15 minutes at 180°C.