For the mushroom duxelles:
Wash and finely slice button mushrooms, and finely dice the shallots and garlic.

Sauté the mushrooms in small batches on high heat with vegetable oil. This ensures a nice caramelisation. You may need to keep adding oil to the pan as the mushrooms will absorb it.

In a separate saucepan, while sautéing the mushrooms, sweat down the finely diced shallots, garlic and thyme. When all the mushrooms have been caramelised, add them to the sauce pan with the herbs.

Add madeira wine and cook off the alcohol. Then, add the chicken stock. Simmer together until the liquid has cooked out.

Lay the mushrooms mixture on a tray and place in the refrigerator until chilled. Once chilled, pour the mushroom mixture onto a chopping board and chop as finely as possible with a large chef's knife. Add parsley.

Place the chicken breast in a food processor and pulse until it is puréed while adding the double cream.

Mix in the chicken mousse with the mushroom mixture. Season with salt and pepper.

For the crêpes:
In a large bowl, beat the egg.

Mix in milk and season with salt.

Sieve the flour and add to the egg and milk mixture.

Pass the mixture through a sieve into another bowl to get out any lumps.

Add the finely chopped chives to the mix and set aside.

In a large non-stick frying pan, heat a small amount of butter. Once melted, pour in one ladle-full of crêpes mix and spread across the bottom of the pan.

Heat until it is cooked but with no colour, which should take about 30 seconds.

Flip it over on to the other side for approximately 10 seconds until it is fully cooked. Repeat for 2nd large crêpe.

Red wine sauce
Meanwhile, make the red wine sauce. Heat the oil in a large pan, then fry the beef trimmings for a few minutes until browned on all sides. Stir in the shallots with the peppercorns, bay and thyme and continue to cook for about 5 minutes, stirring frequently, until the shallots turn golden brown.

Pour in the vinegar and let it bubble for a few minutes until almost dry. Now add the wine and boil until almost completely reduced. Add the stock and bring to the boil again. Lower the heat and simmer gently for 1 hour, removing any scum from the surface of the sauce, until you have the desired consistency. Strain the liquid through a fine sieve lined with muslin. Check for seasoning and set aside.

Putting it all together:
1. Season the beef fillet with salt and pepper.
2. Heat a medium size frying pan, add some vegetable oil. Sear the meat on all sides until golden. This should take approximately 1 to 2 minutes.
3. Once seared, place beef in refrigerator for approximately 20 to 30 minutes until completely chilled.
4. Roll out puff pastry until it is 0.5cm thick, lay in a tray and put back in the fridge until needed.
5. After chilling, brush the seared beef fillet with mustard.
6. Lay out the two crêpes overlapping each other halfway.
7. Spread the duxelles over the crêpes, making a thin layer around 0.5cm thick.
8. Place the beef fillet in the centre of the two crêpes. Roll the crêpes around the beef fillet until it is completely covered. Carefully with cling film, wrap the beef as tight as possible and place back in the refrigerator for around 10 to 15 minutes.
9. Remove the puff pastry from the fridge and brush the whole sheet with a beaten egg yolk. Place the beef in the centre and roll so that the pastry completely covers it. Make sure it is as tight and as neat as possible, trim off any excess pastry and place on a tray with parchment paper underneath.
10. Carefully score the pastry in whatever pattern you'd like, making sure to not cut through the pastry. Glaze the whole Wellington with egg yolk and place in the oven on a tray at 210°C for around 20 to 25 minutes, or until an internal probe thermometer reaches 32°C.
11. Allow to rest for 10 minutes and carve. Serve with some crispy potatoes, roasted garlic, spring greens and gravy.