Mushroom, Puy Lentils and Ale Pie

There are so many variations of the 'Mushroom, Lentil and Ale Pies', in vegetarian cookbooks, at veggie-friendly eateries, on blogosphere and even the Vegetarian Society in the U.K has its own version
Mushroom, Puy Lentils and Ale Pie: Mushroom, Puy Lentils and Ale Pie