Preheat the oven to 190° C.
Bore holes through the turkey breasts roughly 1-2 cm wide. Stuff the holes with the cranberries. Brush the turkey breasts all over with the olive oil, then roll in the poppy seeds. Season well and arrange on a baking sheet. Roast for 50-60 minutes until the turkey is firm yet slightly springy to the touch. Using a skewer, pierce the turkey gently at the thickest point to ensure that its juices run clear and it is cooked through.
Meanwhile, heat the chicken stock in a saucepan over a moderate heat until reduced by half. Whisk in the butter and cashews nuts and set to one side.
Cook the potatoes for the purée in a large saucepan of salted, boiling water for 15-20 minutes until tender. Cook the broccoli florets for 3-4 minutes in a large saucepan of salted, boiling water until tender then drain. Combine the potato and broccoli in a food processor with the egg yolk and some seasoning. Puree until smooth, then spoon into a piping bag fitted with a star shaped nozzle; reserve to one side.
Cook the Brussels sprouts, carrots and onions in separate saucepans of salted, boiling water; cook for roughly 10-15 minutes for each then drain and combine in the same bowl.
Preheat the grill to hot.
Melt the butter and sugar together for the caramelised vegetables in a frying pan over a moderate heat. Swirl the pan to help dissolve the sugar, cooking the mixture until you have a light caramel. Lower the heat and add the vegetables, swirling them to coat in the caramel.
Remove the turkey and allow it to rest, covered loosely with aluminium foil. Re-heat the sauce.
Pipe the purée onto serving plates and glaze under the grill for 1-2 minutes until golden and set. Remove carefully from the grill and allow the plates to cool to one side.
Heat the sunflower oil for the garnish in a heavy-based saucepan until very hot. Shallow fry the julienned potato and carrot for 1-2 minutes until golden and crispy. Drain on kitchen paper.
Slice the turkey breast into 1-2cm slices. Arrange on the serving plates and spoon the caramelized vegetables next to the turkey. Top with the crispy julienned vegetables.
Spoon the sauce on top of the turkey and garnish the dish with sprigs of thyme leaves before serving.
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For top tips on protecting you and your family when preparing raw meat and poultry, visit Food Safety in the Home and view the full Food safety at home video.