Creamy vegan mushroom and leek pie recipe

Ingredients

• 1 x 375g sheet ready-rolled puff pastry*
• 1 tbsp maple syrup
• 1 tbsp plant-based milk
• 1 tbsp vegetable oil
• 2 tbsp olive oil
• 2 leeks, washed and finely chopped
• 2 garlic cloves, crushed
• 1 tbsp dried tarragon
• 600g chestnut mushrooms, thickly sliced
• 1 tsp sea salt flakes
• 1 tsp cracked black pepper
• 3 tbsp plain flour, plus extra to dust
• 240ml white wine*
• 480ml vegan vegetable stock (use 1 stock cube)
• 240ml oat or soy cream (or use coconut milk)
• 160g frozen sweetcorn
• 1 tbsp miso paste
• juice of ½ lemon
• 1 tbsp wholegrain mustard