Add tbs of olive oil to your pot. Add the leek, and garlic. Let saute till golden.
Then add your parsnips and carrots, add salt and pepper and let cook.
Microwave potatoes until for tender and cube, set aside.
once the pan with your vegs becomes dry add your frozen peas and a dash of chicken stock, and then cook until parsnips and carrots are fork tender.
spoon this vegie mixture into a seperate bowl and set aside.
Now in the same pot add 2 tbs of canola oil, and then 2 tbs of flour. Let cook for about two mins.
then whisk in your chicken stock, when it begins to thicken add butternut squash.
to this season generously to taste with s & p.
to this add back in the veggie mixture, along with the potatoes.
Pour this into your baking dish, mine was about 8x8, and cover top with thawed piece of puff pastry. (the not so low fat part, but so yummy!!)
bake in a 400*f oven until top become puffed up and golden brown, let cool and serve.