Portobello mushroom, caramelised onion and brie Wellington

• For the onions, heat olive oil in a large frying pan on medium heat. Add onions and cook until very soft and starting to caramelise (about 10 minutes). Add brown sugar, balsamic vinegar and water, reduce heat and cook until you have a jam-like consistency (about 15 minutes). Stir in thyme and season to taste with salt and pepper, then refrigerate to cool completely.
• Brush any excess dirt off mushrooms with a pastry brush or paper towels (see tip below), then remove stalks.
• Heat a good drizzle of oil in a large frying pan on a medium-high heat. Cook mushrooms four at a time, skin-side down, for about 5 minutes (add more oil between batches as needed). Use a fish slice to flatten mushrooms gently in the pan; you are aiming to get almost all the moisture out of them. Gently flip over and cook for a further 5 minutes until Place skin-side-up on a plate lined with paper towels. Leave to cool slightly then refrigerate to cool completely.
• Preheat oven to 200°C. Line an oven tray with baking paper and lay puff pastry on top. Roll it out slightly to make it a little thinner. Place half the caramelised onions down the length of the pastry, leaving a 1cm gap at each end. Top onions with half the camembert and then six mushrooms, slightly overlapping. Now add another layer of six mushrooms (the two layers of mushrooms sit on top of each other), then camembert and onions
• You should have a kind of log shape in the middle of your square of pastry. Lift the pastry from one side to cover the filling (using the baking paper to help guide you), followed by the other side. Use your fingers to gently seal the pastry together. Then seal the ends by folding over and gently pinching. Turn the Wellington seam-side down on the tray.
• Brush egg wash lightly over Wellington and bake for 30-35 minutes or until pastry is puffed and golden. Some cheese may ooze out, but not to worry: these crusty, bubbly bits are delicious so just serve them along with the Wellington!
• Melt butter in a frying pan until starting to bubble, add sage leaves and fry for 1-2 minutes until crispy. Garnish Wellington with crispy sage leaves. Let Wellington rest for a couple of minutes before using a very sharp knife to cut it into thick slices (one for each diner). Serve with chutney or relish and salad.

Top tips:

• Don’t wash mushrooms under water – they’ll absorb too much moisture. Brush dirt off with a pastry brush or paper towels instead.
• Keep pastry cold (defrost in fridge) until ready to use. This will make it much easier to work with.