21-Day Aged Sirloin, Béarnaise Sauce And Roasted Potatoes

Preheat the oven to 230ºC/ 210ºC (fan)/ gas 8

Before you start cooking, take your steak out of the fridge, open the packet and let it adjust to room temperature

Cut your waxy potatoes into quarters

Peel and slice your red onion[s] into thick rings

Cut a piece (or two!) of baking paper (or tin foil) approx. the size of an A3 sheet of paper

Lay the chopped potatoes, red onion rings and garlic clove[s] (skin on) in the middle of the baking paper piece[s], then transfer to a baking tray (or two!)

Add a drizzle of olive oil, your cracked black pepper and a generous pinch of salt

Cut a knob of butter into small cubes and dot them all over the potatoes

Scrunch the edges of the baking paper together around the potatoes to form a sealed parcel[s]

Put the baking tray[s] in the oven for 40 min or until the potatoes are golden and cooked through

Once the potatoes are in the oven, separate the egg yolk[s] from the white[s] by cracking your egg[s] over a small bowl and catching the yolk in the shell

Transfer the yolk from one shell half to the other several times, until all the whites are in the bowl and you are left with the yolk in the shell, then add the egg yolk[s] to a separate bowl

Tip: Hold on to those egg whites! They're perfect for meringues or a protein-rich omelette (they freeze well too)

Chop your parsley finely, including the stalks

Heat a pot over a low heat, then add your crème fraîche and your white wine vinegar and cook for 1 min

Add the egg yolk[s] and cook for 1-2 min further, stirring constantly, or until the sauce has thickened

Stir through the chopped parsley and season with a pinch of salt – this is your béarnaise sauce

Once the potatoes have been in for 25 min, heat a large, wide-based pan (preferably non-stick) over a high heat

Pat your sirloin steak[s] dry with kitchen paper, drizzle with vegetable oil and season with a pinch of salt on both sides and once very hot, add the steak to the pan

For rare, cook for 2-3 min max on each side; for medium-rare, cook for 3-4 min on each side; for medium, cook for 4-5 min on each side then once the steak is cooked, transfer to a plate to rest, reserve the pan

While the steak is resting, return the pan to a medium heat

Wash your spinach, then pat it dry with kitchen paper

Add a knob of butter and the spinach to the pan and cook for 2-3 min or until starting to wilt, then season with a pinch of salt

Meanwhile, return the béarnaise sauce to a very low heat and cook for 1 min or until warmed through