1 x 225g block puff pastry, defrosted (or use ready rolled puff pastry)
4 portobello mushrooms (preferably organic ones as they taste better)
4 tsp Henderson’s Relish or vegan Worcestershire sauce (optional)
1 large red onion
1 tin of tomatoes
1 clove garlic
1/2 tsp salt and black pepper
1 tsp sugar
2 tsp balsamic vinegar
Soya milk for glazing
Preheat the oven to 220c.
Chop the onion and garlic and fry gently in a non-stick saucepan for 10 minutes until softened. Add the tomatoes, vinegar, salt, pepper and sugar and simmer for around 15 minutes.
Divide the pastry into quarters, roll out into squares approx. 20cm long and leave to stand for a few minutes. Brush the gills of the mushrooms with the Henderson’s Relish if using.
Spoon the tomato mixture into the mushrooms, being careful not to over-fill them. Place them on a square of pastry, fold the pastry over the mushrooms so that the corners overlap at the top and press the edges together as firmly as possible. (The mushrooms can be prepared in advance up to this point.)
Lightly brush with soya milk, cut a couple of steam slits in the top of the pastry and bake for 25 minutes.