Preheat oven to 180°C. Cut beef into 2½cm-3cm cubes. Season with salt and pepper, add 2 tbsp oil, and mix well. Heat a large frypan over a medium-high heat. Brown the beef in 2 or 3 batches. Remove each batch and place in casserole dish.
Reduce heat in the pan, add a little oil, add onion, celery and carrots, cook for 1–2 minutes, and stir occasionally.
Sprinkle in the flour and stir until the vegetables are coated. Gradually pour in stock and add the tomato paste, stirring well. Add the potato and herbs, stir until the mixture boils. Add to the casserole dish, stir to combine. Cover the casserole dish, place in oven, and cook until the beef is very tender. Stir every 40 minutes or so, add water if needed to keep the ingredients just covered.