Preheat the oven: preheat the oven to 180°C / 350-375°F / Gas Mark 4-5.
Season: use kitchen tongs to place short ribs onto chopping board in one flat layer. Then pat ribs with dry with paper towel. Season both sides with salt and pepper.
Sear: place large cast iron pan onto stove, add olive oil and turn heat to high. Place short ribs into the pan and sear for at least 3 minutes each side to brown the meat. Once browned, remove and transfer to a chopping board with layer of paper towel.
Vegetables: without rinsing the pan, add carrot, celery and onion, fry for 2 to 3 mins on high heat. Then add the garlic, tomato paste and dried parsley, stir to combine and allow to cook for a further 2 to 3mins.
Sauce: add the diced tomatoes to the pan. Then use the tongs to place the braised ribs on top. Crush the boullion cubes with your fingers and sprinkle over the combined tomato vegetable mixture. Turn the heat to low and allow the dish to simmer.
Bay leaves: place the bay leaves directly into the centre of the pan. Put the lid on then place onto the middle shelf of the oven. Allow them to cook for 3 hours, removing (use oven mits and a heat proof surface) and rotating to the other side every hour.
Polenta: cook the polenta according to the packet instructions, add 2 teaspoons of butter and stir to combine.
Gremolata: add the chopped parsley, lemon zest and minced garlic to a small jug. Use a mini whisk to combine.
Serve and garnish: dollop cooked polenta into bowls. Top with spoonfuls of the cooked vegetable sauce mix. Then place cooked ribs on top. Season the finished dish with freshly cracked black pepper. Then sprinkle the gremola over the top.