Season the lamb with salt and pepper and dust with flour. In a large pot, melt the butter with the oil over medium heat. Fry the lamb in batches for 5 minutes each side until browned. Remove, set aside, and repeat. When all the lamb is brown, add the onion and cook for 5 minutes, stirring occasionally. Add the carrot and celery, stir. Cook for 5 minutes. Deglaze with the wine. Reduce. Add the tomatoes and swede and return the lamb to the pot. Stir
Tie the herbs into a bouquet garnis and add with the garlic and chicken stock. When boiling, reduce heat to medium low and cook covered for one hour. Remove the lid. Add the potatoes. Cook for 20 minutes, then add the shallots, carrot and turnip and cook for a further 15 minutes. Check for seasoning.
While the lamb is cooking, make the puree by placing the celeriac, butter and cinnamon in medium saucepan over medium high heat and cook for 20 minutes, stirring regularly until the celeriac softens. Remove the cinnamon and add the chicken stock. Cook for a further 10 minutes. Add the cream. Puree with a stick blender or food processor. Check for seasoning. Keep warm. Serve the navarin in a warmed bowl with the celeriac puree.
