Pork Wellington

STEP 1: BUILD THE DUXELLES AND DRIVE OUT THE WATER

Melt the butter with 1 tbsp of the olive oil in a large frying pan over medium heat. Add the onion and cook for 5 minutes until soft, then add the mushrooms, apple, garlic, thyme leaves and thyme sprigs. Cook for 12-15 minutes, stirring often. The mixture will release a great deal of liquid and then take it back; keep going past the point where it looks done. Pour in the cider and reduce until the pan is dry. Stir in the sage, then season with the full teaspoon of salt and the black pepper - more than feels comfortable, because this layer has to season the pork around it as well as itself. The pan should be audibly dry and the mixture should hold its shape when you draw a spoon through it, with no liquid running back into the gap. Discard the thyme sprigs, spread the duxelles on a plate and chill completely.

STEP 2: SEAR THE FILLET AND CHILL IT HARD

Pat the pork fillet dry and season all over with the 1/2 tsp salt and 1/4 tsp pepper. Get a heavy pan very hot with the remaining 1 tbsp olive oil and sear the fillet for about 90 seconds per side, turning until browned all over. Do not cook it through. Transfer to a plate, smear the wholegrain mustard over the hot surface, and refrigerate for at least 30 minutes until cold. A warm fillet sweats inside the pastry, and searing both builds flavor and sets the surface so it gives up less water later.

STEP 3: ASSEMBLE THE PORK CORE

Score the chilled fillet along its length, cutting about two-thirds of the way through, and open it out like a book. Squash the black pudding into a log the length of the fillet, lay it in the channel, and fold the pork back around it so the pudding is fully enclosed. If the fillet springs open, reshape it and tie it at 1-inch intervals with kitchen string, then snip the string away once the meat is wrapped. Lay a large sheet of cling film on the work surface and cover it with overlapping slices of prosciutto in a rectangle wide enough to wrap the fillet completely, then lay the gammon and smoked gammon over the prosciutto.

STEP 4: WRAP, THEN CHILL AGAIN

Spread the cold duxelles evenly over the cured meats, leaving a clear inch (2.5 cm) at the long edges. Set the stuffed fillet along one long edge and use the cling film to roll the whole thing into a tight cylinder, twisting the ends like a cracker to compress it. Refrigerate for at least 30 minutes. A firm, cold cylinder is what lets you wrap pastry around it without stretching or tearing, and it buys the pastry a head start in the oven before the filling warms up.

STEP 5: ENCASE IN PASTRY

Roll the puff pastry to the thickness of a pound coin and cut two rectangles: the base about an inch wider than the cylinder on all sides, and the top piece noticeably larger again. Lay the base sheet on parchment and dust it with the semolina flour. Unwrap the chilled cylinder, set it on the semolina, and brush the exposed pastry border with beaten egg. Drape the larger sheet over the top, working it down against the sides without stretching it, and press the edges together, pushing out trapped air as you go. Trim to a neat border and crimp all the way around, checking the underside for any open seam. Brush all over with egg, score the top in a close diagonal pattern cutting through the top layer only, and scatter with flaky sea salt. Chill for 20 minutes while the oven heats.

STEP 6: BAKE ON A PREHEATED TRAY

Put a heavy baking sheet in the oven and preheat to 425F (220C). Slide the Wellington, still on its parchment, straight onto the hot sheet so the base starts cooking on contact. Bake for 20 minutes, then reduce to 375F (190C) and bake a further 25-30 minutes until the pastry is a deep, dark gold all over. Aim for 145F (63C) at the center of the pork for juicy meat, or 160F (71C) for well done. If the top browns before the center is there, tent it loosely - never cover the base.

STEP 7: REST AND SLICE

Lift the Wellington onto a wire rack rather than a plate and rest it for 15 minutes; a rack lets the last of the moisture escape downward instead of condensing under the base. Slice thickly with a serrated knife, using a sawing motion. Each slice should show a black pudding bullseye inside pale pork, ringed by the cured meats and the dark duxelles. Serve with something sharp: a spoonful of apple sauce, pickled red cabbage, or a cider gravy made from the searing pan.