Add the vegan butter to a saucepan and let it melt. Then add the chopped onions and garlic and fry in the butter until very soft and translucent.
Mix the flour and a little of the unsweetened coconutmilk together until it becomes a paste. Then add the rest of the coconutmilk to the paste and whisk it in so that the flour and coconutmilk is well combined and free of lumps.
Add the flour and coconutmilk mix to the saucepan along with the soy sauce and vegetable stock and whisk together.
Bring to a boil, whisking constantly. Let it boil for a few minutes until it thickens and becomes a nice, pourable consistency.
Add some black pepper and sea salt to taste.
Pour gravy over sweet potato fries. Top with vegan cheese if desired.