Peel the potatoes and cut them into chunky, similarly sized pieces so they cook at a consistent rate. Thinly slice the onions and set them aside. If you’re using a carrot, peel and dice it into small pieces. Keep the cooked beef ready nearby so everything can be added without interrupting the cooking process.

Place a heavy-bottomed saucepan over medium-low heat and add the beef dripping or butter. Once melted, add the sliced onions and cook gently for about 8–10 minutes, stirring occasionally until they become soft and translucent. Avoid browning them too much, as the goal is to build a mellow, savory base for the potatoes.

Add the potatoes to the pan and stir them gently to coat them with the onion mixture. Pour in enough beef stock to come partway up the potatoes rather than completely submerging them. Add the optional bay leaf and Worcestershire sauce, if using, then bring the liquid to a gentle simmer.

Stir the chopped or shredded roast beef through the potatoes. Cover the saucepan with a lid and reduce the heat to low. Allow the mixture to simmer gently for approximately 30–40 minutes, stirring occasionally to prevent sticking. Add a small splash of stock or water if the bottom becomes too dry before the potatoes are tender.

Check the potatoes with a fork. They should be very tender, with some pieces beginning to break down and thicken the cooking liquid. Use the back of a wooden spoon to gently crush a few pieces against the side of the pan, leaving the rest intact. Remove the bay leaf and taste before adding salt and black pepper.

Remove the pan from the heat and let the stovies rest for a few minutes so the flavors settle. Stir in a small knob of butter or a little chopped parsley if desired. Spoon into warm bowls and serve immediately with oatcakes, crusty bread, or pickled beetroot for a traditional Scottish-inspired meal.