Pre-heat your oven to 200C or gas mark 7.

Place the beef fillet on a roasting tray and brush with a little olive oil and season with salt and pepper.

Road the piece of beer for 15 minutes for medium-rare, or 20 minutes if you prefer medium.

Once cooked, remove the beef from the oven and allow to cool completely before placing in the fridge for at least 15 minutes.

In the meantime, finely dice the mushrooms.

Heat a little olive oil and the nob of butter in a frying pan and fry the mushrooms for 10 minutes or until they begin to soften.

Add the garlic, wine and thyme and cook for a further 10 minutes until the liquid has soaked up and the mushrooms have begun to stick to each other creating a a coarse paste.

Place the mushrooms to one side, and again allow these to cool before progressing to the next stage.

Once the beef and mushrooms are both cool, take the puff pastry and cut off a piece roughly 1/3 of the total pastry.

Roll the smaller (1/3) piece of pastry into a rectangle roughly one inch longer and wider than the beef fillet and place on a piece of grease proof paper.

Place a little of the mushroom mix down the centre of the pastry and place the beef fillet on top.

Spread the mushroom pate over the beef fillet before spooning over the chopped mushroom mix, ensuring that it sticks to the fillet.

Roll out the second, larger piece of pastry until it is big enough to entirely encase the fillet.

To seal the top piece of pastry to the bottom piece gently press the edges with a fork.

Trim the pastry so that it forms a neat rectangle.

Beat the two egg yolks and brush the beef wellington all over. Leaving a little of the egg yolk behind.

Take any scraps of pastry and use these to decorate the wellington as I did with leaf shapes.

Use any remaining egg yolk to brush the decorations.

Chill the wellington in the fridge for at least 30 minutes or for up to 48 hours.

When ready to cook, pre-heat the oven to gas mark 6 or 180C. Make sure the baking sheet you intend to cook the wellington on is also in the oven at this stage.

Once the baking tray is nice and hot ,slide the wellingtonon to the tray and cook for 25 minutes for medium-rare or 30 minutes for medium.

Once the pastry is crisp and golden, remove from the oven and allow to rest for roughly 10 minutes before serving.