1. Fillet and debone fish. Salt lightly. 2. Set the oven on hot air at 50°C. 3. Place the trout fillets in a GN and cover tightly in cling film. Perforate holes in the cling film and smoke with hay using a smoking gun. 4. Remove the cling film and bake for 10 minutes. 5. Boil the potatoes in 200ml of the chicken stock and the saffron. 6. Sauté the sliced onions in 70g of the butter. Add the cleaned and chopped Jerusalem artichokes and keep going for 5 minutes. 7. Pour in the remaining chicken stock and cook for 20 minutes. 8. Finish with double cream, simmering for another 5 minutes. 9. Purée the soup in a hot mixer and finish with the remaining 30g of butter. 10. Strain through a fine sieve. 11. Flake the smoked fish into a soup bowl, top with your saffron-flavoured potatoes and pour the hot soup over. 12. Serve with bread on the side.