Place marinade ingredients into a non-reactive bowl and stir gently to combine. Add beef, mix. Cover and marinate for at least 6 hours or overnight. Drain beef and reserve marinade liquid.
Cut the carrot and parsnip into evenly sized 2-3cm chunks.
Heat 2 tbsp reserved marinade liquid in a large frypan over a medium heat. Add carrot and parsnip and cook, stirring occasionally, for about 10 minutes until they turn golden. Set aside.
Heat 3 tbsp reserved marinade liquid in the same frypan over medium-low heat. Cut each garlic clove in half, add these and the eschalots and cook, stirring occasionally, for about 20 minutes, until they also turn golden. Set aside.
Toss beef in seasoned flour and shake off excess.
Heat 2 tbsp of reserved marinade liquid in the same frypan and brown beef in batches over medium-high heat. Transfer beef to a large, heavy-based pot.
Add more marinade liquid (if necessary) to frypan on a low heat. Cook onion and celery, seasoned with salt to taste, until softened. Gradually add red wine, stirring well to scrape up any pieces from the base of the pan. Bring to boil, then simmer until wine is reduced by one-third. Pour mixture over beef, along with stock and bouquet garni. Simmer over low heat for about 1½ hours. Add reserved vegetables and orange zest and cook for a further 45-60 minutes, until beef is very tender.
Scatter with fresh thyme leaves and ground pepper, and serve with soft polenta or mash.