75 g (3 oz) portobellini or small field mushrooms, sliced
2 fillet steaks
100 ml (3½ fl oz) red wine
125 ml (4 fl oz) good-quality beef stock
25 g (1 oz) cold butter, diced
salt and pepper
mashed potato, to serve
Heat half the olive oil in a large frying pan and cook the lardons over a medium-high heat for 2–3 minutes, until golden. Add the mushrooms and cook for a further 2–3 minutes, until softened and golden.
Meanwhile, heat the remaining oil in a separate pan and cook the steaks over a medium-high heat for 2–3 minutes on each side, or until cooked to your liking. Transfer to a plate and keep warm.
Pour the wine into the empty pan and stir over a medium-low heat, scraping up any bits stuck to the bottom, until the wine becomes syrupy. Add to the bacon mixture, then pour in the stock and simmer hard to reduce by half. Season to taste, then gradually whisk in the butter until the sauce is smooth and glossy.
Arrange the steaks on warmed plates and serve immediately with the bourguignon sauce and hot mashed potato.