Pre heat oven to 200c/400f/ gas 6. Line a large baking tray with grease proof paper.

Peel and finely chop onion, then trim and finely chop Celery. Heat 1 tablespoon oil in a large frying pan over medium-high heat, then add the chopped vegetables. Cook for 10 - 15 mins, or until golden. Meanwhile finely chop mushrooms.

Peel and crush garlic, then add the chopped mushrooms. Cook a further 5 mins or until the mushrooms start to soften. Add the mustard, wine, salt and pepper, then reduce the heat to low. Cook 5 to 10 mins, or until all the liquid has boiled and bubbled away. Set aside to cool

Add the cooled mushroom mixture and breadcrumbs to a large bowl. Pick and finely chop and add the parsley leaves, then pick and chop the thyme add and stir well. Taste and season again if needed.

Cut the sheets of puff pastry in half lengthways so you have 4 equal sized pieces. Spoon a quarter of the mushroom mixture along the middle of the length of pastry, moulding it into a long sausage shape with the back of the spoon.

Brush the Almond milk along the pastry edges, then carefully fold one of the long sides of pastry up over the filling. Press the edge to seal, then crimp with a fork. Repeat with the remaining mixture until you have 4 long rolls. Then cut each length into four pieces.

Place the roll on the prepared baking tray, brush with Almond milk and sprinkle with sesame seeds. Pop on the bottom shelf of the hot oven for 25 to 30 mins, or until golden, then serve