Heat the oven to 180c/fan 160c/gas 4. Melt a knob of butter in a frying pan then add the celery, onion, 1 tbsp sage and 1 tbsp thyme. Season and cook until soft, about 5 minutes. Tip the bread, pine nuts and apricots into a bowl and pour the onion mixture over. Season again and mix well. Lay the meat out flat and spread the stuffing over it. Roll up and tie with string.
Sprinkle the outside of the joint with the remaining thyme, sage and some seasoning. Put in a baking tin and cook for 2 hours. Leave to rest for 20 minutes, remove string then cut into thick slices.