Chateaubriand with Classic Béarnaise and Pommes Anna

⏱ 100 min · Serves 4

The grand old steakhouse showpiece, done properly at home: a thick centre-cut fillet roasted rosy and carved at the table, a glossy tarragon-scented béarnaise, and a crisp golden tower of butter-layered potatoes. Worth every minute.

Per serving: 1090 kcal · 48.0g protein · 36.0g carbs · 86.0g fat

Ingredients

• 1 centre-cut beef fillet (chateaubriand), about 800g, tied
• 2 tbsp neutral oil
• 30g unsalted butter, for the beef
• 2 thyme sprigs and 1 garlic clove, halved
• Flaky salt and coarsely cracked black pepper
• 900g waxy potatoes (Desiree or Yukon Gold), peeled
• 150g unsalted butter, clarified, for the potatoes
• 1 tsp fine salt
• 3 tbsp white wine vinegar
• 3 tbsp dry white wine
• 1 small shallot, very finely chopped
• 4 tarragon stalks, leaves picked and chopped, stalks reserved
• 1 tsp black peppercorns, cracked
• 3 large egg yolks
• 200g unsalted butter, melted and warm, for the béarnaise
• 1 tbsp chopped chervil or flat-leaf parsley
• Lemon juice, to taste

Method

1. Take the beef out of the fridge at least 1 hour before cooking. Heat the oven to 200C/180C fan.
2. Make the pommes Anna: slice the potatoes 2mm thick on a mandoline. Do not rinse — the starch is the glue. Toss with 60g of the clarified butter and the fine salt.
3. Brush a 20cm ovenproof frying pan or cake tin generously with clarified butter. Arrange a neat overlapping rosette of the best slices on the base, then layer the rest in concentric circles, brushing with butter every couple of layers. Press down firmly.
4. Cover with foil, bake 30 minutes, then uncover, press down again and bake a further 30–35 minutes until deep golden and tender to a skewer. Rest 10 minutes before turning out.
5. Meanwhile make the béarnaise reduction: simmer the vinegar, wine, shallot, tarragon stalks and cracked peppercorns until reduced to about 2 tbsp. Strain and cool slightly.
6. Season the beef heavily. Heat the oil in a heavy ovenproof pan until shimmering and sear the fillet hard on all sides, 6–8 minutes total. Add the 30g butter, thyme and garlic, baste for a minute, then roast 15–18 minutes for medium-rare (52C in the centre).
7. Rest the beef on a warm plate, loosely covered, for 12 minutes — it will climb to 55C.
8. Finish the béarnaise: whisk the yolks with the reduction in a bowl over barely simmering water until thick and ribbony. Off the heat, trickle in the warm melted butter, whisking constantly, until glossy and thick. Stir in the tarragon and chervil, season, and sharpen with a squeeze of lemon. Keep somewhere warm, not hot.
9. Turn out the pommes Anna, cut into wedges. Snip the strings from the beef, carve into thick slices across the grain, spoon over resting juices and serve with the béarnaise alongside.