Field Mushroom, Walnut and Thyme Filo Pie | Marcus Wareing

Ingredients

• 100g puy lentils
• 70g butter
• 2 onions, thinly sliced
• 1 garlic clove, finely grated
• 1/2 bunch thyme, 2/3 of it tied together with string, the remaining 1/3 leaves picked
• 8 large field (or flat) mushrooms, thinly sliced
• 100g walnuts
• 1 tbsp vegetable oil
• 100g cream cheese
• 2 tbsp milk
• 50g cheddar cheese, grated
• 7 large sheets of filo pastry
• sea salt and freshly ground pepper