- 1½ tbsp olive oil
- 4 200gm pieces of beef tenderloin fillet
- 150 ml red wine
- 200 ml beef stock
- 500 gm floury potatoes, such as sebago
- 750 ml pouring cream (3 cups)
- 2 tsp thyme leaves, plus extra to serve
- 1 garlic clove, finely chopped
- To serve: coarsely chopped flat-leaf parsley
- 200 ml pouring cream
- 100 gm Roquefort, coarsely crumbled
- 1For gratin dauphinoise, preheat oven to 200C. Thinly slice potatoes on a mandolin and layer in a buttered 1.5-litre baking dish, seasoning generously to taste as you go. Bring cream, thyme and garlic to the simmer in a saucepan over medium-high heat, then pour onto potato to cover (depending on the size of your baking dish, you may not need all the cream). Place baking dish on an oven tray and bake on the lowest shelf of the oven until bubbling and golden and potato is tender when pierced with a skewer (50 minutes to 1 hour). Scatter with parsley and extra thyme just before serving.
- 2Heat oil in a large frying pan over medium-high heat, add beef, season to taste and cook, turning once, until browned (2-3 minutes each side). Transfer to oven and roast until cooked to your liking (4-5 minutes for medium-rare), then transfer beef to a warm plate and rest for 5 minutes. Deglaze pan with wine and simmer over medium-high heat until reduced by half (2-3 minutes). Add stock, simmer until reduced to a glaze (2-3 minutes) and season to taste.
- 3Meanwhile, for Roquefort sauce, combine cream and half the Roquefort in a small saucepan over low heat and stir occasionally until melted and combined (2-3 minutes). Season to taste and keep warm.
- 4Drizzle glaze over beef and serve with gratin dauphinoise. At the table, spoon Roquefort sauce over beef and scatter with remaining Roquefort.