Place the fennel and pepper in a small dry saucepan over medium heat.
Swirl the saucepan regularly until the fennel and pepper are fragrant, then remove from the heat.
Add the salt and use a mortar and pestle to pound to a powder.
Place the samphire, cornichons, mint, parsley, lemon juice and olive oil in a bowl and mix to combine.
Place the cornflour and half the self-raising flour in a large bowl. Gradually add the soda water and whisk to combine. Place the remaining flour in a small bowl.
Heat oil in a large deep saucepan or wok over medium heat until the temperature reaches 180°C.
Working in batches, dust the prawns with the flour, then dip into the batter and carefully lower into the oil.
Cook for 3 minutes or until crisp and golden. Drain on paper towel.
Sprinkle with fennel salt and top with finger lime pearls.
Serve with fresh samphire salsa.