Preheat oven to 90°C. Season the cheeks generously with salt and pepper, then drizzle with 1 tbsp extra virgin olive oil. Sear in a pan over a high heat until browned, then set aside. Sauté the vegetables in 1 tbsp of extra virgin olive oil in a heavy-based saucepan over moderate heat, then add the beef, wine and stock. Simmer for 20 minutes, fit the lid, then bake for 23 hours.
Remove the beef cheeks from the saucepan, strain the liquid (discarding the solids) then boil the liquid until reduced to 1 cup. Add the sherry.
Steam the cauliflower until tender, then puree in a blender with the butter and a generous amount of salt. Wrap in muslin and hang for 1 hour to remove excess moisture. Mix in the saffron.
Toss the carrots in 1 tbsp extra virgin olive oil, then barbecue until lightly blackened. Toss the mushrooms in the remaining olive oil, garlic, rosemary and celery salt. Increase oven to 210°C, arrange in a roasting pan and bake for 20 minutes.
Rewarm the cheeks in the oven for 4 minutes then serve with the cauliflower purée, carrots, mushrooms and sauce.