Method
1. Warm a large frying pan (or casserole if cooking in the oven) for 2 mins. Add 1 tbsp oil and the beef. Fry for 5-6 mins, turning, till the beef is browned.
2. While the beef fries, peel and finely chop the onion. Trim and peel the carrots and slice them into 1cm thick rounds. Trim the dry ends off the celery stick and slice it. From this point on, follow the method for the slow cooker or the oven.
3. In the slow cooker: Tip the beef into a 3½ ltr slow cooker and add the chopped veg. Peel and chop the potatoes. Add them to the dish. Drop in the bay leaf and the thyme sprigs. Season with a crack of pepper.
4. Crumble the stock cube into a heatproof jug and stir in 750ml boiling water to dissolve it. Pour it into the slow cooker, add 1 tbsp Worcester sauce, pop on the lid and cook for 5 hrs at medium.
5. When the casserole has cooked for 4½ hrs, sift the flour into a bowl. Add 1 tsp baking powder and a pinch of salt. Whisk to mix. Chop the butter and rub it into the flour with your fingertips to make a fine, sandy mixture. Coarsely grate the cheddar. Finely chop the rosemary leaves. Stir them into the flour, then add 6-8 tbsp cold water and stir with a fork to make a soft dough. Roll into 8 dumplings.
6. Taste the beef casserole and add a pinch more salt or pepper if you think it needs it. Carefully rest the dumplings in the slow cooker. Put the lid back on and cook for another 1 hr. Ladle the beef casserole and dumplings into warm bowls to serve.
7. In the oven: Heat your oven to 160°C/Fan 140°C/Gas 3. Pop the browned beef on a plate. Add the chopped veg to the casserole dish with 2 tbsp water. Fry, stirring now and then, for 5-8 mins till the veg has started to soften.
8. While the veg fries, peel and roughly chop the potatoes. Add them to the dish. Tip the beef back in, with any juices from the plate. Drop in the bay leaf and the thyme sprigs. Season with a crack of black pepper.
9. Crumble the stock cube into a heatproof jug and stir in 750ml boiling water to dissolve. Pour it into the dish, add 1 tbsp Worcester sauce, pop on the lid and slide into the oven. Gently cook for 2½ hrs.
10. When the casserole has cooked for 2 hrs, sift the flour into a bowl. Add 1 tsp baking powder and a pinch of salt. Whisk together with a fork or whisk to mix. Chop the butter and rub it into the flour with your fingertips to make a fine, sandy mixture. Coarsely grate the cheddar. Finely chop the rosemary. Stir them into the flour, then add 6-8 tbsp cold water and stir together with a fork to make a soft dough. Roll into 8 round dumplings.
11. Take the casserole out of the oven and take off the lid. Turn the heat up to 190°C/Fan 170°C/Gas 5. Taste the beef casserole and add a pinch more salt or pepper if you think it needs it. Carefully rest the dumplings in the casserole dish. Slide back into the oven without the lid, and bake for 30 mins. Ladle the beef casserole and dumplings into warm bowls to serve.