In a large pot, sauté the mushrooms, onion and garlic in vegan margarine for 3 – 5 minutes, until onions are translucent.
Reduce heat, add 3 cups vegetable stock and allow to simmer for 30 minutes (to intensify the mushroom flavour).
In a second saucepan, bring several cups of water to the boil. Add potatoes and simmer until potatoes are soft. Drain water and mash potatoes, adding a little vegan margarine and salt & pepper to taste.
Pre-heat oven to 190C.
Add quinoa, carrots and beans to the mushroom pot and simmer for another 10 minutes, stirring often. If the mixture becomes too dry, add more vegetable stock.
Add gravy powder to the quinoa mixture a little at a time and stir until it reaches desired consistency. Season with salt & lots of cracked pepper.
Press pastry into a greased baking tin and fill with the quinoa mixture. Top with mashed potato and a spray of oil (optional).
Bake for 20 minutes or until the potato peaks are a lovely golden colour.