Peel the potatoes and halve any larger ones so they’re all roughly the same size. Simmer in a pan of salted boiling water for 20 mins or till soft.
Trim, peel and finely chop the carrots and onion. Finely chop the celery and garlic. Finely slice the sage leaves.
Warm 1 tbsp oil in a large frying pan over a medium heat. Fry the mince for 5 mins to brown it
all over. Stir often. Add the chopped veg and sage. Season. Turn the heat down slightly and cook gently for 5 mins. Stir often.
Pour 300ml boiling water into the frying pan. Cover and simmer for 20 mins till the mince sauce is thick. Stir now and then.
Meanwhile, drain the cooked potatoes and tip into a bowl. Mash well. Set aside to cool for at least 10 mins. Once cool, tip in the flour and season. Use your hands to form it into a dough.
Roll the potato dough into sausages, then cut on an angle into rough 2 cm thick dumplings. Bring a pan of water to the boil. Drop the dumplings in batches into the hot water. Simmer for 3-4 mins till they float to the surface. Transfer them to the mince pan with a slotted spoon.
Gently stir the dumplings to coat with the sauce. Taste and adjust the seasoning if you think it needs
it. Cover and set aside to keep warm.
Shred the cabbage. Warm 1 tsp oil and 1 tbsp water in a pan over a medium heat. Cook the cabbage for 4-5 mins till softened. Serve the mince and potato dumplings with the cabbage.