Preheat the oven to 200°C (bottom/top heat).
Wash and pat the meat dry. Truss if necessary.
Mix together the honey, lemon juice, orange marmalade, thyme, ginger and cayenne pepper to make the marinade.
Heat the oil in a roasting pan and brown the meat well on all sides. Pour in the broth and brush the roast with a little of the glaze.
Put the roast in the preheated oven and roast for about 90 minutes - basting frequently with the marinade.
Wash the potatoes and cook in boiling water for 20 minutes until done. Drain and allow the excess moisture to evaporate.
Trim the mushrooms and rub them gently with paper towel.
Peel the onions. Add them along with the mushrooms and potatoes to the roast the last 15 minutes of cooking.
Slice the roast. Arrange the meat along with the vegetables on a platter. Serve garnished with thyme.