Preheat your oven to 160°C (320°F).

Season the Osso Bucco with sea salt and black pepper. Lightly dust the pieces with plain flour and shake off the excess.

Heat a large, heavy-based frying pan over medium heat. Add olive oil and brown the Osso Bucco in batches until each piece is evenly seared. Remove and set aside.

In the same pan, melt the butter, then sauté the onion, garlic, carrots, and celery until softened and slightly caramelized.

Pour in the Rosé wine to deglaze the pan, stirring to loosen any browned bits. Add the chopped tomatoes, thyme, and beef stock, then bring to a gentle simmer.

Transfer the browned Osso Bucco to a large casserole dish. Pour the simmering liquid over the meat, ensuring everything is submerged. Cover with a layer of baking paper and then tightly seal with foil.

Place the dish in the preheated oven and cook for 4 hours. Remove the foil and continue to cook for an additional 30 minutes to develop a deeper flavor.

Serve hot with mashed potatoes, soft polenta, or caper gremolata.