Season and Sear Oxtail: Season oxtail with salt and pepper, dust with flour, and sear until golden brown. Once golden, remove the oxtail from the pan.
Sauté Vegetables: In the same pan, add diced shallots, celery, and carrots.
Add Aromatics and Tomato Paste: Add garlic, thyme, rosemary, and tomato paste, cooking for a bit.
Deglaze with White Wine: Add white wine and seasoning, allow to evaporate.
Add Stock and Reduce: Follow with the stock and reduce by half.
Braise Oxtail: Return the oxtail to the pan, add water and Bouquet Garni, cover, and cook on a low heat for two and a half hours until tender.
Reduce and Season the Sauce: Remove the oxtail, strain the liquid and reduce it. Season with lemon juice, salt, and pepper.
Prepare the Garnish: Mix chopped parsley, lemon zest, diced shallot, salt, pepper, diced tomato, lemon juice, and rapeseed oil.
Serve: Serve the oxtail with mashed potatoes, glaze with the sauce, and garnish with the parsley mixture.