French onion and beef pie with gruyère crust

Heat a tbsp of oil in a large, non-stick frying pan and, over a high heat, brown the beef in batches, adding a tbsp more oil if needed. Scoop each batch out onto a plate afterwards.

Put another tbsp of oil plus the butter into the same pan with the onions and reduce the heat. Fry gently for 20-25 minutes or until soft. Stir in the sugar and cook for a further 20 minutes, stirring often. They should be golden brown and really soft by this stage – if they’re not, carry on cooking until caramelised. Heat the oven to 160C/fan 140C/gas 3.

Scoop out ³/4 of the onions and put aside. Stir the garlic into the remaining onions and cook for another 3-4 minutes, then add the flour, stirring until it has disappeared. Turn up the heat, still stirring, and gradually add the white wine, followed by the beef stock. Keep stirring until the liquid just comes to the boil, then carefully tip into a casserole with the beef chunks and any plate juices.

Put a lid on the casserole and bake in the oven for 2 hours, then stir in the reserved onions. Bake for another 30 minutes or until the beef and onions are meltingly tender and the sauce has thickened.

Take the casserole out of the oven and turn it up to 180C/fan 160C/gas 4.

Simmer the potatoes in a large pan of water for 8-10 minutes or until tender. Drain well and put back into the pan to steam-dry for a couple of minutes, then mash with the butter and milk, and lots of seasoning.

Use a slotted spoon to scoop out the beef and onions from the casserole into a large pie dish. Spoon over enough of the gravy to just cover the meat (you’ll reheat the remainder to serve with the pie).

Dot the mash all over the top then use a palette knife to spread smooth. Scatter over the three cheeses.

Bake the pie for 40 minutes until the cheese is bubbling and browning, and the filling piping hot. Serve with the reheated extra gravy and some vegetables.