Leek, mushroom & goat's cheese strudels

Name: Leek, mushroom & goat's cheese strudels
Prep time: 20 min
Cook time: 40 min
Total time: 1 h
Cuisine: British
Ingredients: 500g leeks , thinly sliced; 150ml low-sodium vegetable stock; 175g chestnut mushroom , sliced; 4 large sheets filo pastry; 1 tbsp olive oil; 85g soft-rinded goat's cheese or vegetarian alternative; 1 tsp poppy seeds