300gpuff pastry (see link above if you want to make your own)
Preheat oven to 200°C
Soak your dried porcini in boiling water
Peel the celeriac and cut into cubes. Put on a baking tray with olive oil, salt, pepper and three unpeeled garlic cloves. Put in the oven to roast
Finely chop the shallot. Peel and finely chop the remaining garlic clove. Add some olive oil to a small frying pan on a low heat and gently sweat the onion and garlic for 10 minutes
Roughly chop the wild mushrooms and add to the pan. Pick the thyme leaves and add. Season and let the mushrooms gently cook down for 10 minutes
After 20 minutes in the oven check your celeraic and turn them. Remove the three garlic gloves and put to one side
Once cooked take the mushrooms off the heat and leave to cool slightly. Then stir in the pine nuts, dill and breadcrumbs
Take the celeriac out of the oven when soft and golden. Cool and then add to the mushroom mix. Squeeze the roasted garlic cloves and add the soft garlic to the filling.
Take the porcini out of the soaking liquid and finely chop. Add to the filling. If it's looking a little dry add a splash of the soaking liquid.
Put a piece of parchment paper on a clean surface. Roll out the puff pastry on the parchment sheet into a square, about 25cm by 25cm.
Add your filling to one half of the rectangle - leaving a 2cm gap around the edge.
Mix a splash of milk into your beaten egg and brush the edges of the pastry. Using the parchment paper fold the other side of the pastry over the filling and press the edges to seal. If you like you can press the edges with a fork and use a knife to add a criss cross pattern to the top.
Brush the wellington with the egg/milk mixture. Transfer the baking parchment to a baking tray (you can cut away the excess paper if you like). Put the wellington in the oven for about 35-40 minutes until it is crisp and golden.
This has quite an intense mushroomy flavour. You could swap out the fresh wild mushrooms for chestnut or portobello if you prefer. Or if that's what you have in your fridge!