1. Place the salt, sugar, rosemary, pink peppercorns and orange peel into a bowl and mix.
2. Allow to stand for 10 minutes.
3. Mix the elderflower syrup and the olive oil together in a large flat bottomed bowl. Separate out half the mixture and keep it safe, you’ll need it later in the process.
4. Place the trout fillets into the bowl with the elderflower mixture for 3 minutes a side.
5. Take the orange peel and rosemary from the salt mixture and reserve.
6. In a clean flat bottom bowl, equally disperse half of the sugar/salt mixture.
7. Place the trout fillets on the salt and cover the fillet equally with the remaining salt mixture.
8. Leave the trout fillets in this position for 20 minutes.
9. Once the 20 minutes has elapsed, remove excess salt mixture from the trout fillets by quickly running under cold slow-running water, then gentle pat dry with a clean kitchen towel.
10. Place the trout fillets in the remaining elderflower mixture for 3 minutes before removing and placing on a clean tray. Portion to desired size.