Preheat the oven to Gas Mark 6, 200°C, fan 180°C. Gently fry the onion in the butter for 5 mins. Turn the heat to high, add the mushrooms, then cook for 5-10 mins until golden and the pan is dry. Cool for 5 mins.
Put the other ingredients in a large bowl and season well. Tip in the mushrooms then mix well with your hands. Set aside 350g (12oz) stuffing for the neck of the turkey. Firmly press the rest into 16 mounds in greased bun tins or squash into balls. Bake for 20 mins until dark golden.
Freezing and defrosting guidelines
In order to enjoy optimum flavour and quality, frozen items are best used within 3 months of their freezing date. Always defrost and heat thoroughly before eating. For more tips on freezing and defrosting food, read our article Love Your Freezer.