Crumble the tempeh. Breaking it up by hand is the easiest method.
Add all sausage ingredients to a large pan (crumbled tempeh, vegetable stock, soy sauce, garlic powder, onion powder, sage, thyme, pepper, nutmeg, and chili flakes.) Stir together.
Bring to a boil, then simmer on medium-low heat for about 15 minutes, or until the tempeh has absorbed all of the liquid.
Gravy
Mix the oil into the tempeh sausage. Then mix in the flour. Let cook for about a minute.
Whisk in the non-dairy milk. Bring to a simmer on medium heat for about 5 minutes, or until thickened.
Add salt and pepper to taste.
To serve, ladle the sausage gravy over the biscuits.