For the Fennel Pesto, roughly chop one fennel bulb, including fronds, and place into a large fry pan with butter and olive oil. Cook over low heat, stirring often, until caramelised, about 20 minutes. Add pepitas, lemon juice and season to taste. Cook for a further 3-4 minutes until softened.
Transfer the fennel and pan juices to a blender. Pulse several times to break up the fennel. With motor running, slowly add the grape seed oil until emulsified. Set aside until needed.
For the Pernod Prawns, Pernod, lemon juice, chilli flakes, tarragon and salt in a bowl and whisk well to combine. Add the prawns and toss to coat well. Set prawns and marinade aside in the fridge to marinate for 20 minutes.
For the Fried Fennel, combine rice flour, water, chilli flakes and salt in a bowl and whisk until smooth. Set the batter aside in the fridge to rest for 10 minutes.
Meanwhile, remove fronds from fennel bulb and set aside until needed. Remove tough outer layers of fennel and discard. Slice fennel bulb in slices lengthways, 5mm thick, across bulb.
Trim and separate brussel sprout leaves.
Heat grapeseed oil in a medium saucepan or deep fryer to 200C.
Remove batter from fridge. Dip sliced fennel, reserved fennel fronds and brussel sprout leaves in batter and fry, in batches, for 3-4 minutes, until crisp. Set aside to drain on kitchen paper until needed.
To finish the Pernod Prawns, heat a large fry pan over medium high heat. Add 60ml grape seed oil and cook prawns until opaque in the centre and lightly golden on both sides.
To serve, place one slice of fried fennel on each serving plate. Top with 4 prawns per plate. Scatter brussel sprout leaves and fennel fronds over each plate. Sprinkle with extra toasted pepitas and a quenelle of fennel pesto.