Retro over here, but up-to-date in US diners! The brown sauce is optional!
Generous knob of butter
1 large onion, finely sliced
1 large (about 275-300g) floury potato, such as maris piper, unpeeled but cut into 1cm chunks
350ml hot beef stock
200g corned beef, cut into 1cm chunks
100g peas (optional)
1 tbsp grain mustard (or to taste)
1 tbsp Worcestershire sauce (or to taste)
2 eggs (optional)
Melt the butter in a frying pan over a medium-high heat. Fry the onion, stirring frequently, until golden, then add the potatoes. Stir to coat with butter, cook for a minute or so, then pour in the stock. Simmer for about 15-20 minutes until the potatoes are really tender and the stock has almost evaporated, adding more hot water if necessary.
Heat the grill. Stir in the corned beef, peas, mustard and Worcestershire sauce. Turn up the heat and cook, stirring occasionally, for about five minutes, until they’re heated through. Put the pan under the grill for about five minutes until the top is crisp and golden.
Meanwhile, if you’re topping the dish with eggs, heat a small frying pan, add a little more butter and fry the eggs to your liking. Serve on top of the hash.