A treat dinner after a long day on the pastry bench. The thing that lifts surf and turf above a slab of meat is the butter melting into it, and you don’t need the full steakhouse Café de Paris production to get there. A faux béarnaise does the same job: the tarragon, shallot and vinegar that make a béarnaise, beaten into soft butter rather than whisked into an emulsion, with all the flavour and no fear of it splitting. With the butter made ahead and the steaks brought up to temperature in the water bath, the cooking on the night is a hard sear and a few minutes of seafood.
Yield and time
- Makes: serves 4
- Ahead: 15 minutes for the butter (a day or two before); 1-2 hours in the water bath
- Hands-on: about 25 minutes on the night
Ingredients
The tarragon butter, a faux béarnaise (makes a little extra, it freezes)
- 125g unsalted butter, softened
- 2 tablespoons tarragon, finely chopped
- 1 small shallot, very finely diced
- 1 tablespoon white wine vinegar
- 1 teaspoon Dijon mustard
- a squeeze of lemon
- fine sea salt and black pepper
The turf
- 4 sirloin (porterhouse) steaks, about 300g each, 3cm thick
- 1-2 tablespoons neutral oil
- a knob of butter, a couple of sprigs of thyme, 2 crushed garlic cloves (for basting)
- salt and pepper
The surf
- 12 raw king prawns (frozen), thawed, peeled with tails on, deveined
- 12 scallops, patted very dry
- a little oil and butter
To serve
- triple-cooked chips
- rocket or watercress, dressed with a sharp lemon vinaigrette
Make the butter ahead
Soften the diced shallot in the vinegar for 10 minutes first, it takes off the raw bite and stands in for the reduction a real béarnaise would simmer down. Then beat the shallot and vinegar, the tarragon, Dijon, lemon and a good pinch of salt and pepper into the softened butter until evenly green-flecked. Taste, and adjust the salt and lemon.
Scrape it onto a sheet of baking paper, roll into a log about 4cm across, twist the ends, and chill until firm, at least two hours, ideally overnight. It keeps a week in the fridge and months in the freezer.
Sous vide the steaks
Season the steaks with salt and pepper and seal each into a sous vide bag in a single layer, a sprig of thyme in the bag if you like. Set the water bath to 54°C for medium-rare (50°C for rare, 58°C for medium) and lower the bags in. An hour is enough for a 3cm steak, and up to two does no harm, once the meat reaches the water’s temperature it can’t take on any more, so the timing is forgiving. This is the part that makes it foolproof: edge-to-edge pink, no grey band, no guesswork.
Dry, then sear hard
Lift the steaks out and pat them completely dry with paper towel, a sous vide steak comes out wet, and a wet steak will not crust. Heat the oil in a heavy frying pan until it’s just smoking.
Sear the steaks hard, in batches if they won’t all fit, because a crowded pan steams instead of browning, for 45-60 seconds a side, just long enough to build a deep brown crust. They’re already cooked through, so you’re only colouring the outside; any longer and you start to cook into that perfect middle. In the last few seconds drop in the butter, thyme and crushed garlic, tilt the pan, and spoon the foam over the top.
A sous vide steak needs only a minute’s rest, not the usual five, the inside is already at an even temperature, so there’s nothing to settle. Move the steaks to a warm plate while you cook the seafood.
The seafood, same pan
The prawns and scallops don’t want the water bath, they’re a 90-second job in a hot pan, and gentle sous vide heat only turns them soft and poached. Straight into the pan they go, where a fast, hot sear is exactly what’s good for them.
Wipe the pan if it’s caught, leave a film of the steak butter, and bring it back to a high heat.
Scallops first: lay them in with space between, in two batches if the pan won’t take all twelve without crowding, press lightly, and leave for 60-90 seconds until the underside is a deep caramel. Flip, 30-60 seconds more, they should be just opaque in the middle and no further. Out they come.
Prawns next, thawed right through and patted very dry, because frozen prawns hold a lot of water and a wet prawn steams grey instead of searing: 1-2 minutes a side until they turn pink and curl. The moment they’re opaque they’re done; a second too long and they go rubbery.
Plate
Chips down first, steak alongside, a thick disc of the tarragon butter set on the hot steak so it slumps and runs. Prawns and scallops tucked in beside, with any pan butter spooned over them. The dressed rocket on the side, sharp and cold against the richness.
Eat straight away, while the butter’s still melting into the plate.