Place a large casserole pan over a medium heat, add two tablespoons of olive oil and the butter, followed by the onions and fresh herbs. Cook for around 20 minutes, or until soft and turning golden, stirring occasionally.
Slice the beef into rough 2cm strips and add to the pan along with the mushrooms, tomato purée and a good pinch of salt and pepper. Stir in the vinegar, beer, flour and hot stock and bring to the boil, then reduce the heat to low, cover with a lid and simmer for 1 hour 20 minutes, or until the sauce has thickened and the meat is tender.
Meanwhile, get on with making your pastry. Add the flour, suet, butter and a pinch of salt into a bowl and use your fingertips to rub the fat into the flour until it resembles coarse breadcrumbs. Stir in 125ml cold water, gently bringing it together– be careful not to work it too much. Wrap the pastry in cling film and place in the fridge for later.
Preheat the oven to 180°C/350°F/gas 4. Carefully ladle the stew into a pie dish (roughly 24 x 30cm and 4cm deep), then lay over the slices of cheese.
Dust a clean work surface and a rolling pin with flour, then roll out the pastry so it’s roughly 1cm thick and a little larger than your pie dish. Brush the edges of the dish with a little beaten egg, then carefully unroll the pastry over the top. Trim any excess pastry and pinch the edges in so it’s nice and tidy (use any excess pastry to make a cute cut-out to place on top, if you like). Brush the top with a little more egg and place in the hot oven for 45 to 50 minutes, or until the pastry is beautifully golden. Delicious served with steamed greens.