Place the ox cheeks in a large stainless steel container and cover with the stout, wine, rosemary, thyme, garlic, celery, bay leaves, carrots, leeks and onions. Cover and marinate in the refrigerator overnight.
Preheat the oven to 330 degrees F. Drain the meat in a colander, reserving the marinade and vegetables.
Heat some vegetable oil in a large heavy-bottomed saucepan and gently fry the the marinated vegetables for a few minutes. Add the tomato paste and stir over a low heat for 1 minute. Slowly add the marinade, stirring constantly to incorporate. Bring to a boil and simmer until the liquid reduces by half. Add the stock and the meat, sprinkle with salt and pepper and bring back to a boil. Cover with a lid and reduce the heat to a gentle simmer, then transfer to the oven and roast until the meat is tender, 2 hours 30 minutes to 3 hours.
Once the meat is cooked the sauce should be sufficiently thick. If it is not, remove the meat and simmer the liquid on the stovetop until it thickens up in consistency, a few minutes. Place the meat back into the finished sauce to serve.
Serve the braised ox cheeks with smoked cauliflower mash and crispy bone marrow, or with buttery mashed potatoes and green vegetables.
It's difficult to put an exact time on the cooking for this dish, as oven temperatures can vary; sometimes an extra half an hour may be required depending on the meat itself. The best way to check is by pushing a skewer or small sharp knife into one of the cheeks to see if it feels tender, and also taste the meat. This is a dish that works really well for an overnight slow braise in the oven on a lower temperature. You can cook it in the oven at 176 degrees F for 6 to 8 hours.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.