For the oat pastry
175g rolled oats
50g wholemeal flour
120g chilled unsalted butter or lard, diced
1 egg yolk
For the filling
1kg braising steak, cut into cubes
2 level tbsp plain flour
2 tbsp olive oil or lard
1 onion, very finely chopped
2 sprigs thyme
1 sprig rosemary
1 bay leaf
About 1 litre of Legbiter Ale
1 strip of orange rind
1 egg, beaten with milk, to make eggwash
1. To make the pastry, put the rolled oats in a food processor and whiz until you have a fine flour. Transfer to a large bowl with the wholemeal flour, a pinch of salt and the butter or lard.
2. Rub in the fat lightly but thoroughly with your fingertips, until the mixture resembles breadcrumbs. Work in the egg yolk and enough cold water (2-3 tablespoons) to form a dough. (All of this can all be done in the food processor, if you prefer.) Wrap the pastry in clingfilm and place in the fridge for 30 minutes.
3. Roll the steak in the flour. Heat the oil or lard in a casserole and cook the onion until soft and lightly coloured. Transfer the onion to a bowl, then brown the steak in the pan in batches. Add a little more oil if necessary. When all the steak has been browned put it in the casserole with the onion and herbs. Add the Legbiter ale, scraping at the base of the casserole with a spatula to deglaze it and add flavour to the stew. Put in the orange rind and bring to the boil. Turn down to a slow simmer and cook for 1½-2 hours until the meat is tender. Season to taste with sea salt and freshly ground black pepper. Allow to cool.
4. To assemble the pie, preheat the oven to 200C/gas mark 6, then roll the pastry out on a lightly floured worksurface to about ½cm thickness (no thinner). When rolled it should be 3cm larger all round than the pie dish you have chosen. Put the braised steak and juice in a pie dish. Insert a 'pie chimney’ if you have one.
5. Brush the edge of the dish with eggwash and lay the pastry over the top, pressing the edges to the dish. Brush with more eggwash, cut a vent in the centre for steam to escape during cooking, and bake for 30 minutes or until the pastry is pale gold and crisp, and the contents of the pie are bubbling.