Mix the zest, half the lime juice, ginger, honey and soy sauce in a bowl. Add the turkey and leave to marinade for 15 minutes. Meanwhile, gently boil the potatoes in lightly salted water with half of the broccoli. Drain, add the garlic, milk and remaining lime juice, then mash well. Keep warm. Fry the turkey with the marinade in a pan. Add the remaining broccoli, celery, peas and onions, stirfrying for 4-5 minutes until everything is heated through. Transfer to an 8" ovenproof dish, then spoon on the mash mixture. Bake at 200 degrees C for 25-30 minutes.