Wash the turkey roast, pat dry, season with salt and pepper, and place in the baking dish.
Preheat the oven to 200 °C (392 °F), gas mark 3.
Peel two oranges with a knife and remove the individual segments. Squeeze the third orange. Rinse the parsley, shake dry, pluck the leaves, and chop. Clean and wash the spring onions and cut into rings.
Arrange the orange segments, parsley, and spring onions over the roast.
In a bowl, mix the orange juice, mustard, cream, and poultry stock together. Season with salt and pepper.
Pour the sauce over the roast and braise in the oven at 200 °C (392 °F) for 45-50 minutes, until the internal temperature reaches 74 °C (165 °F).