Preheat the oven to 200°C (gas mark 6) and line a baking tray with baking paper.
Microwave the chopped potato for about 3 minutes until soft.
Cook the onion and mushroom in a frying pan with a bit of oil until slightly caramelised and add the softened potato, cook for a minute. Turn off the cooker.
In a bowl, blend the tofu, nutritional yeast, tahini, lemon juice, soy sauce, soya milk, garlic puree, salt and pepper with an immersion blender.
Add the creamy tofu mixture to the cooked vegetables in the frying pan, mix well.
Unroll the puff pastry sheet and cut into half lengthwise so you have now two long rectangle shapes.
Put half of the creamy tofu filling in the middle of a rectangle all the way from one end to the other end like a line running through the rectangle.
Fold over both sides of the pastry and seal the openings with a bit of water and press gently with a folk.
Repeat the steps for the other rectangle using the remaining filling. Cut into any size you want, small or big. I usually make small bite size ones.
Bake in the preheated oven (200°C, gas mark 6) for 25 to 30 minutes or refer the baking time suggested on the pastry package.