Heat the oven to 180°C/fan 160°C/gas mark 4.
Put the celery, onion, garlic and ginger in the bottom of a shallow casserole dish. Bash the juniper berries lightly in a small pestle and mortar (or in a bowl with the end of a rolling pin) and add them to the casserole. Add the orange juice and zest and drizzle with a good glug of vegetable oil. Give it a good mix and spread out to make a bed for the duck legs.
Rub the za’atar all over the duck legs and lay them on top of the vegetables in the casserole. Season well with salt and pepper. Now simply place in the oven and cook, uncovered, for roughly one-and-a-half hours, depending on the size of your duck legs. The duck is done when the flesh easily pulls away from the bone with the touch of a fork.
Meanwhile, remove the seeds from the pomegranate. The best method for this is to score the tough outer skin into quarters. Submerge the fruit in a large, deep bowl of cold water and, using your hands, gently pull apart the quarters and ease out the seeds with your fingers. The seeds sink to the bottom and the skin and pith will float to the top and can be scooped away. Drain off the water and the seeds remain. (Don’t leave the seeds in the water too long – tip them out onto kitchen paper to dry.)
Remove the duck from the oven. Pour off the duck fat from the vegetables. Allow the duck to cool for a few minutes to make removing the meat from the bones easier.
Shred the duck and skin and tip into a large mixing bowl. Tumble together with the roasted vegetables and then turn out onto a generous serving platter.
Make the dressing by combining the lemon juice, pomegranate molasses and olive oil.
Serve before the duck cools completely: Drizzle the dressing all over, then top with the pomegranate seeds and sliced spring onions.