Season the beef fillet thoroughly with salt and pepper and place a large frying pan over a medium heat. Add the oil to the pan and, once the pan is nice and hot, add the beef, sprinkling over the chopped thyme. Sear on all sides, turning every 1-2 minutes to colour until it is browned evenly and rare in the centre. Take the beef out of the pan, coat with the Pommery mustard and leave to rest in the fridge.
To make the mushroom mix, add the butter to the same pan and allow to melt, then add the chopped mushrooms and sauté until golden brown. Take out of the pan and set aside.
Add the chopped garlic and shallots to the same pan and soften. Re-add the mushrooms, cooking until the liquid evaporates. Pour in the Madeira and bring to the boil, then reduce by half. Add the cream, and stir until the mixture has thickened and is beginning to darken in colour. Season with salt and pepper and leave to one side.
To make the pancakes, whisk the eggs, milk and flour together into a smooth batter. Add a little oil to a heated frying pan. When the oil is hot, add enough batter to form a very thin layer in the base of the pan. Cook until golden on the underside, then flip the pancake over to cook the other side, remove from the pan and leave to one side. Repeat the process until all of the pancake mixture is used up.
Blanch the spinach leaves quickly in boiling water and then cool in iced water. Remove the leaves and dry thoroughly.
On a board place a sheet of cling film and lay 3 pancakes onto it, making sure the pancakes overlap so that the cling film is fully covered. Add a single layer of the spinach leaves on top.
Evenly spread the mushroom duxelle mixture over the spinach and lay the beef on top. Tightly wrap the pancakes, spinach and mushroom mix around the beef using the cling film. Leave to cool in the fridge, overnight if possible.
Roll out the puff pastry into a thin sheet about 1/4 cm thick – if pre-rolled it will need to be rolled thinner.
Take the Wellington out of the fridge, remove from the cling film and place on top of the pastry. Brush the edges of the pastry with the egg wash, roll up and then use the egg wash to seal the edges. Set aside while you prepare the vegetables.
Prepare the artichokes for the salad and vinaigrette. Remove the coarse bottom leaves until only the pale yellow leaves remain. Using a sharp knife, cut the top two-thirds off to expose the centre of the artichoke. Carefully trim any outer leaves off the base, ensuring the natural shape remains.
Heat the oil in a heavy based pan and cook off the fennel seeds. Add the shallot, leeks, garlic and thyme, sweating until opaque, then add the wine, chicken stock, lemon juice and white wine vinegar to the pan and bring to the boil. Carefully add the artichokes, cover with a cartouche and bring the liquid back up to the boil.
Simmer for 3-4 minutes, then remove the pan from the heat and allow the artichokes to cool in the cooking liquor. Once cooled, remove the artichokes and pass the cooking liquor through a sieve, reserving the strained liquid. Cut the artichokes in half and use a teaspoon to remove the chokes from the centre.
For the artichoke purée, heat the cream in a pan until gently simmering. Stir in four of the artichokes – eight halves – to warm through. Transfer to a blender and blitz until smooth, seasoning to taste. Set aside until required, remembering to reheat before serving.
Preheat the oven to 180°C/gas mark 4 before you intend to cook the Wellington.
Cook the Wellington in the oven for 20-25 minutes or until the pastry is golden brown. When it is cooked the internal temperature should be about 49-52°C . Check by inserting a thin metal skewer in the centre of the beef – on removal the skewer should be slightly warm.
Take the Wellington out of the oven when cooked and leave to rest in a warm place for at least 10 minutes.
Meanwhile, prepare the truffle vinaigrette. Using a hand blender, combine 100 ml of the artichoke cooking liquor with the Xanthan gum and olive oil until it forms a coating consistency. Gently warm, then add the remaining artichokes and finely grated truffle and stir until coated.
To serve, spoon a smear of artichoke purée across the plate and arrange the coated artichokes on top, finishing with the shaved truffle. Slice the Wellington into four even pieces and drizzle over the beef jus or gravy.
Recipe courtesy of www.greatbritishchefs.com