Heat coconut oil in large saucepan over medium heat and stir in the mushrooms and shallots (or onion). After 5 minutes, stir in the garlic and let brown for another 5 minutes.
Meanwhile, in a smaller pan prepare a roux which is done by melting vegan butter and gradually adding in the flour. Stir the mixture over medium-low heat for 2 to 3 minutes until thickened and then set aside.
Go back to your browned mushroom pan and gradually add in low-sodium vegetable stock. This will help lift up all of the delicious brown bits stuck to the bottom of the pan. Add the roux mixture to the pan stirring with a whisk and reduce to low heat.
Whisk in onion powder, low-sodium soy sauce/tamari, and molasses. Then slowly incorporate the water, about a ¼ cup at a time, until the desired consistency is achieved.
Notes
For the poutine recipe, I found that ¾ cups of water was the right amount. But if you want it a bit runnier, add a little more water.