A fillet of beef, what's known as a tenderloin in the US, is a princely cut and so it should be because it costs a king's ransom. For a special occasion though, it's a lovely thing to bring to the table and although it's expensive, there's no waste on it. And it's quick to cook. There, that's the self-justification out of the way.
I've cooked it in the past simply rolled in herbs but I was recently given a packet of dried, oak-smoked oyster mushrooms and when I was casting around for what to do with them, Tim from the Artisan Smokehouse suggested grinding them down and rolling a piece of meat in them. Genius. The rest of the recipe followed from there.
In addition to the smoked mushroom crust I made a red wine and mushroom sauce and a mushroom stuffing. In order to stuff a fillet of beef you need to butterfly it, rather nerve-wracking with such an expensive cut if you haven't done it before.
There are two ways to do it, with a single horizontal cut that means the fillet opens out like a book, or (my preferred option) with a double cut that gives you a flatter, bigger piece of meat to play with. I'll try to explain in the body of the recipe but if in any doubt, take a look at this video.
The meat can be prepared and stuffed a day in advance and the sauce can also be made ahead of time and re-heated. The actual cooking and resting of the beef only takes about 45 minutes.
Fillet of Beef with Smoked and Fresh Mushrooms (serves 6-8)
About 750-800g fillet of beef, from the thick part of the fillet
About 5g smoked dried mushrooms, ground to a powder
Salt and freshly ground black pepper
For the stuffing:
20g dried porcini mushrooms, soaked in hot water
100g fresh mushrooms (I used chestnut but wild mushrooms would be good too), finely chopped
1 medium onion, peeled and finely chopped
1 clove of garlic, peeled and crushed
2-3 small sprigs of thyme, leaves stripped
30-50g pâté (I used Brussels pâté)
A knob of butter and 1 tbsp oil
For the sauce:
1 small onion, finely chopped
100g fresh mushrooms, thinly sliced
Butter for frying
1 heaped tbsp plain flour
The mushroom soaking liquid, strained through a fine mesh
1 glass red wine
About 300-400 ml chicken or beef stock (depends how many you're feeding)
Salt and freshly ground black pepper
First make the stuffing. Cover the dried porcini mushrooms with hot water and leave to soak for 20 minutes, then fish them out and chop finely, reserving the soaking liquid for the sauce. Heat the butter and oil in a deep frying pan and cook the onions until soft and golden. Add the garlic, the fresh mushrooms, the chopped porcini and the thyme and cook until the mushrooms have given up their moisture. Season to taste.
Remove from the heat, place in a bowl and allow to cool, then mix in just enough pâté to make the mixture cling together. Take a piece of cling film, place the stuffing in the middle and wrap and roll to form a sausage a little shorter than your piece of beef. Place in the fridge to firm up.
To prepare the meat, first remove any silvery skin on the outside with a sharp knife. Lie the fillet on your chopping block and slice along the long side about a third of the way up the thickness of the fillet. With smooth strokes, follow the cut through so it folds out like a book. One side will now be thicker than the other side.
Make another lengthways slice through the thick part, from the centre towards the outside edge, stopping about 2cm short. Open it out so you have a flat piece of meat, effectively with a double hinge. Honestly, it's easiest to watch the video.
Place the stuffing in the middle, roll up and tie with string, hopefully more neatly than I did. Put a layer of the powdered smoked mushrooms on your work surface or in a large flat dish (best not done with the window open on a draughty day).
Roll the beef fillet in this, coating well, and season with black pepper. Set aside in the fridge but take it out half an hour before you want to start cooking.
To make the sauce, heat the butter in a pan and fry the sliced mushrooms until just cooked. Remove and set aside. In the same pan, fry the chopped onion gently until soft and golden. Stir in the flour and continue to cook on a gentle heat for a couple of minutes. Add the red wine and stir well, then gradually add the mushroom soaking liquid and stock. Cook, stirring, until the mixture has thickened and reduced. If you want a smooth sauce, give it a whizz with a hand blender. Season to taste, put the mushrooms back in and set aside.
To cook the beef, pre-heat the oven to 200C/400F/Gas Mark 6. Season the meat with salt to taste, heat a tablespoon or so on oil in a roasting tin and quickly sear the beef on all sides until browned. Place in the oven and cook for about 15 minutes for rare (this joint will be ruined if you overcook it), then remove from the oven, cover loosely with foil and leave somewhere warm to rest for 15 minutes.
Slice and serve with the mushroom and red wine sauce and the vegetables of your choice. A celeriac mash would be good with it, or Dauphinoise potatoes. And of course a decent, robust red wine: we drank a Rioja Gran Reserva.