Heat a heavy based saucepan over med-high heat. Add half the oil and sear beef in batches for a few minutes on each side until evenly browned. Set beef aside in a bowl.
Add remaining oil to the pan along with onion, carrot, celery, and a pinch of sea salt. Cook for 8 minutes until the vegetables have softened. Add garlic, bay leaves, thyme, rosemary, and tomato paste and cook for a further 30 seconds.
Return beef to the pan with any resting juices and pour in stock and Wilde beer. Cover pan with a tight-fitting lid, transfer to oven and cook for 3 hours or until beef is tender.
While the beef is braising, prepare the potato mash. Add potato cubes to a pot of cold salted water and bring to a simmer. Cook for 20 minutes or until potatoes are tender. Drain potatoes and transfer to a bowl or processor. Add olive oil and mash or pulse to combine. Adjust seasoning with extra salt as required. Set aside.
Remove saucepan from oven and increase heat to 200°c. Shred beef with 2 forks and adjust seasoning with extra salt or pepper if required. Transfer saucy beef to a baking tray or casserole dish and top with potato mash. Return to oven and bake for 30 minutes or until golden.