Remove the chicken meat from the carcass and shred. Discard the bones and set the chicken meat aside.
Warm a little oil in a frying pan over a medium heat and add the onion; cook and stir until soft, about 4 to 6 minutes. Add the curry powder and fry for a further 5 minutes. Add the stock, pickle and tomato puree and cook for a further 20 minutes on a low heat.
Allow to cool, then transfer to a mixing bowl and beat in the mayonnaise and chicken. Spoon into a serving bowl and place in the fridge to chill before serving.