Place the quartered potatoes in a steamer basket over 2-3 inches of water. Heat to a boil, reduce to simmer and cover. Steam them for 8-10 minutes or until fork tender. Remove from heat and move on to the filling.
Heat a large non-stick semi-deep pan on high and add the celery, carrots, onions, garlic, and dash of black pepper.
Cook them for about five minutes or until slightly softened.
Add the mushrooms and cook for another two minutes.
Next, add the peas and the cooked lentils.
In a medium size bowl, whisk together the miso, tomato paste, Liquid Smoke, soy sauce and vinegar, then add the mixture to the pan and stir.
In a small bowl, mix the water and cornstarch until smooth, then add to the pan and stir in to combine.
Bring the filling mix to a simmer, add the herbs and nutmeg.
Reduce the liquid to a consistency you prefer, simmering for about 8 minutes. Let it cool, and adjust the salt to taste. Remember: the Liquid Smoke, the miso and the soy sauce already contain sodium.
Add the potato flakes, nutritional yeast and veg broth to a large bowl and mix until you have a smooth consistency.
Next, add the steamed potatoes to the bowl and roughly mash them. Note: I like a rustic topping with some texture, but you can mash or process them how you prefer).
Add some black pepper, and more liquid (broth or non-dairy milk), and stir well until the mixture comes together to resemble a stiff frosting. Once again, feel free to add salt if you want.
Build the Pie
Preheat your oven to 450 degrees F.
(Optional step) Using one cup of the potato topping, spread loosely on the bottom of the casserole pan.
Pour the filling into a 9 x 13 casserole dish, and begin to scoop the potato topping over the filling to cover it completely. If desired, give the surface a little more texture by scraping a fork across the top.
Cover the pan with foil and bake for 20 minutes.
Then, remove the foil and put the pan under medium heat broiler for 3-4 minutes until potato topping is golden brown….yum.