10Jerusalem artichokes (about 800gm)400 gmunpodded broad beans, poddedFor deep-frying:vegetable oil2 tbspextra-virgin olive oil4skinless blue-eye trevalla fillets (180gm each)2 tbspfinely chopped chives30 gmbutterChicken jus2 tbspolive oil2 kgchicken wings, chopped into 2cm pieces1carrot, peeled and chopped into 2cm pieces1onion, chopped into 2cm pieces1celery stalk, chopped into 2cm pieces½head of garlic, halved crosswise¼bunch thyme1fresh bay leaf
For chicken jus, heat 1 tbsp olive oil in a large saucepan over high heat. Add half the chicken and leave for 3 minutes before stirring, then stir occasionally until chicken is browned all over (3-5 minutes). Remove chicken from pan and repeat with remaining oil and chicken. Add vegetables and garlic to pan and sauté, stiring occasionally, until soft and starting to brown (6-8 minutes). Return chicken to pan, add herbs and 4 litres water, then bring to the simmer. Skim scum and fat from surface, then reduce heat to low and simmer gently until stock is well-flavoured (3½-4 hours). Strain stock through a fine sieve into a clean pan, discarding solids, and reduce stock over medium heat, skimming scum from the surface occasionally, until stock has reduced by two-thirds to 650ml (1-1¼ hours). Strain through a fine sieve and reserve 80ml. Remaining jus can be refrigerated or frozen for later use.
Preheat oven to 180C. Wrap Jerusalem artichokes in foil and roast until tender (1-1½ hours). Set aside to cool briefly, then trim tops of artichokes and slice in half lengthways but not all the way through. Gently scrape the flesh out of artichokes, keeping the skin intact and scraping as much flesh as possible from the skin. Transfer artichoke flesh to a saucepan and reserve flesh and skins separately.
Blanch broad beans in a saucepan of boiling water until tender (2-3 minutes), then refresh in iced water, peel and set aside.
Heat oil in a deep saucepan or deep-fryer to 160C. Add artichoke skins in batches, and deep-fry, turning occasionally, until golden and crisp (2-3 minutes). Set aside to drain on paper towels.
Heat an ovenproof frying pan over high heat, add 1 tbsp olive oil and fish fillets and fry until golden (1-2 minutes). Turn fish over, then transfer pan to oven and roast until just cooked through (4-6 minutes).
Meanwhile, heat artichoke flesh over medium heat (2-3 minutes), crush with a fork and add remaining olive oil and chives and season to taste.
Heat a separate saucepan over medium heat, add 10gm butter and broad beans and stir until warmed through (2-3 minutes).
Heat a separate small saucepan over medium-high heat, add remaining butter and cook until nut-brown, or beurre noisette (2½-3 minutes), then add reserved chicken jus, bring to the boil and season to taste.
To serve, spoon crushed artichokes and broad beans onto plates, top with fish, spoon butter sauce over and top with artichoke chips.