Velveted prawns with sweetcorn soup

Serves 4 Prep time 45 mins, cook 2 hrs 10 mins For prawn stock, process vegetables and garlic in a food processor to form a paste. Heat oil in a large saucepan over medium heat, add paste, stir occasionally until golden (10-12 minutes). Add prawn shells, crush with a wooden spoon and stir occasionally until coloured (5-7 minutes). Add herbs, peppercorns, orange rind and 2 litres cold water and bring to the boil. Skim surface (discard scum), reduce heat to low, simmer until well flavoured (40-50 minutes), strain through a muslin-lined sieve to yield 1.2 litres (discard solids) and refrigerate until required.

Combine prawns, cornflour and bicarbonate of soda in a bowl and massage mixture into prawns (2-3 minutes). Transfer to a sieve, rinse under cold water and massage prawns again to remove cornflour mixture. Drain well and refrigerate until required.

Heat olive oil in a saucepan over medium heat, add onion, stir occasionally until golden (5-7 minutes). Add cumin, saut until fragrant (30 seconds-1 minute), add two-thirds of the corn, saut until opaque (5-7 minutes). Deglaze with white wine, add stock, bring to the boil over medium heat, add garlic and chilli oil. Reduce heat to low, simmer until well flavoured and corn is tender (30-35 minutes). Add basil, strain through a fine sieve into a bowl over ice (reserve liquid). Pure solids with enough reserved liquid (about 1 litre) to form a smooth soup, transfer to a saucepan, add potato, saffron and remaining corn. Simmer over medium-high heat until potato is tender (7-10 minutes). Add prawns, stir until barely cooked through (1-2 minutes), season to taste. Serve hot scattered with spring onion and drizzled with olive oil.