Sausage & mash pie

1 Preheat the oven to 200 ̊C/180 ̊C fan/gas 6. Roast the sausages for 30 minutes, turning occasionally until golden and cooked through. Once cool enough to handle, thickly slice and set to one side.

2 Heat the oil in a large, non-stick, ovenproof shallow pan. Add the onion, cover and cook for 10 minutes, stirring occasionally until perfectly softened. Cook uncovered for another 10 minutes until golden. Stir
in the flour and cook for 2 minutes, stirring frequently. Whisk in the beef stock and bring to the boil, while stirring. Add the sausages, kale and sage and simmer for a couple of minutes.

3 Meanwhile, cook the potatoes in plenty of water until perfectly tender. Drain, return to the pan and heat for a minute or so to cook off any water. Add the butter, milk and mustard and mash until smooth. Stir in half the cheese and season to taste. Spoon over the sausage mix, scatter with the remaining cheese and bake for 25 minutes until golden and bubbling.