This recipe from Thermapen, the chef’s best friend, elevates the traditional steak supper with impressive mushroom pithiviers, smokey garlic mash and sweet, buttery carrots. Cook the steaks to temperature with Thermapen to ensure they’re perfectly cooked to suit your preference.


  • Bring the meat to room temperature at least 20 minutes before cooking, and rest it for at least 10 minutes afterwards.
  • The process for the pithivier takes up to 2 hours, so prepare ahead of time.

    Thermapen is for the cook who knows that temperature, not time is the key to creating perfectly cooked food. Quick, accurate and easy to use, it’s designed to take the guesswork out of every cooking challenge. Its versatility makes it ideal for creating perfect roasts, triumphant BBQs, magnificent cakes and delicious jams. The Thermapen range starts from £48.00 (inc VAT)


Serves 2

For the steak

2 sirloin steaks

20g unsalted butter

1 sprigs of rosemary

2 cloves of garlic, gently crushed with skin on

1 tbsp sunflower/vegetable oil

For the pithivier

250g button mushrooms

100g mixed wild mushrooms

1/2 banana shallot, finely chopped

1 garlic clove, crushed

1 sprig thyme, leaves picked

½ finely chopped chives

150ml milk

25g unsalted butter

50ml double cream

1/2 pack of ready rolled puff pastry

1 large egg

50g plain flour

150ml full fat milk

1 tbsp sunflower/vegetable oil plus a little extra for frying

For the mashed potatoes

400g red potatoes

1 smoked garlic bulb

25g unsalted butter

25ml double cream

1 tbsp olive oil

Seasoning to taste

For the chard and carrots

Bunch of rainbow chard

200g carrots cut into batons

1 sprig of thyme

15g unsalted butter

1/2 tsp caster sugar (or maple syrup)

To make the steak

  1. Pat the steaks dry with kitchen paper and season with salt and pepper. Over a medium heat add the oil to the pan, once the oil starts moving, add the butter.
  2. Wait for the butter to sizzle, then carefully lay the steaks in the pan and place the garlic and herbs around the steaks. Once the steaks start to brown turn them over, using a pair of tongs, repeating every 30 seconds, spooning over the juices as you do so. Do this until you’ve reached your desired temperature.
  3. Using your Thermapen, check the temperature of the centre of the steak, you should be aiming for 52°C for rare, 60°C for medium or 71°C for well done.  Allow to rest for around 10 minutes before carving.

To make the pithivier

  1. Tip the button mushrooms into a blender and pulse until finely chopped. Melt the butter in a frying pan and fry the shallot, garlic and thyme leave for a few minutes until soft. Add the blitzed mushrooms and cook for around 10-20 minutes, until all the liquid has evaporated, and the mushrooms are dry. Pour the double cream into the mushroom mix and reduce until the cream coats the mushrooms, then season. This process can take up to 30 minutes, so prepare ahead of time.
  2. Fry the wild mushrooms in a little vegetable oil until soft, then drain off the excess water. Roughly chop half of them and add to the mushroom mix (keep the other half for serving). Leave to sit at room temperature until needed.
  3. To make the pancakes, tip the flour into a bowl with a pinch of salt. Make a well in the centre and whisk in the milk and egg until you make a smooth batter. Add the chives and leave to rest for 1 hour. Heat a little oil in a non-stick frying pan, pour in a ladleful of the batter and swirl around the pan to make a thin pancake. Cook for a minute on each side, until golden. Repeat with the remaining batter to make two thin pancakes.
  4. Roll out the puff pastry and cut out 4 discs, 2 around 10cm in diameter for the bases and 2 around 14cm in diameter for the tops. Place the pastry circles on a baking tray and chill in the fridge for 30 minutes.
  5. When putting the pithivier filling into the pancakes, spoon around 70g of the mushroom mix onto each pancake. Place this onto one of the small circles of pastry, brush the outside edge of the pastry with a little water and then put one of the larger circles of pastry on top. Press the two layers together so that there are no bubbles, and the surface is smooth. Press down with a fork to give a neat, crinkled edge. Chill in the fridge for 10 minutes. Whisk the egg yolks. Brush the egg wash over the pithiviers and put them back in the fridge for up to 1 hour. Egg wash them again and chill for at least another 30 minutes.
  6. Preheat the oven to 200°C/ fan 180°C/ gas 6. Score the tops of the pithivier with the back of a small knife, trying not to pierce the pastry, marking lines in a spiral. Bake until the pastry is golden brown in colour, around 15-20 minutes.

To make the mashed potatoes

  1. Wash, peel and quarter the potatoes. Start cooking the potatoes in cold water, this ensures they cook evenly. Bring to the boil, and simmer until they are soft in the middle. Strain and allow the steam to release.
  2. Mash the potatoes using a potato masher. Avoid using a blender or food processor as this makes them sticky and gluey.
  3. Wrap the whole garlic bulb in tin foil and place in a hot oven for 30-40 mins to soften the cloves. Squeeze the garlic bulb into a bowl with some oil. Add a pinch of salt and mix, then combine with the mashed potatoes.
  4. Gently melt the butter in a pan, or a microwave, until it’s soft enough to mix through the potatoes. Add the butter , cream and the ground smoked garlic to the mash and season to taste.

To make the chard and carrots

  1. Keep the chard leaves whole. Trim any split ends, or damaged leaves.
  2. In a medium sized pan, boil salted water. Simmer the leaves for a few minutes until just cooked. Remove from the water and retain the water for the carrots. Run the chard under cold water and leave to one side until needed.
  3. Preheat the oven to 200°C/ fan 180°C/ gas 6. Parboil the carrots for a few minutes, then drain. Combine the carrots with the butter, sugar and thyme, then bake for 20-30 minutes, until golden.

To finish, slice the steak and serve with a mushroom pithivier and side of smokey mash. Top with the rainbow chard and glazed carrots, as well as a few of the wild mushrooms.

Thermapen Chef

Laura Tulloch