Wipe the king oysters mushrooms down with a clean cloth to remove any grit. Chop 1 inch of the stalk to remove the tough base. Carefully but firmly drag the prongs of a fork down the length of the mushroom to shred the “meat” (this is easier if you lay the mushroom down.) Place in a bowl and gently stir in the tamari, then set aside.
Melt the vegan butter in a large pan over low to medium heat and add the onion, carrots, celery and garlic. Cook for around 5 minutes or until the vegetables are tender. Stir in the flour and cook for another 3 minutes, stirring occasionally. Add the vegetable stock, thyme, and bay leaves and stir in the milk, pepper, and sea salt. Bring the mixture to a simmer. Stir in the shredded mushrooms and reduce the heat to low. Cook the pie filling for 10 minutes or until the liquid has reduced to a pie gravy consistency. Remove from the heat, stir in the peas and set side while you prepare the puff pastry.
Preheat the oven to 420 degrees F.
To prepare the pastry, place a ramekin or pie pot upside down on the thawed pastry and cut a circle a half-inch larger than the dish lip. Repeat with other ramekins. Fill each ramekin with pie filling before laying the pastry over the top. Gently press the edges of the pastry to the side of the ramekin and cut a small slit in the center of each pastry top. Brush a small amount of dairy-free milk on top (not the sides) of the pastry and place the pies in the oven for 15 minutes or until the pastry top is golden