Heat vegan butter in a saucepan over medium-high heat.
Cook your vegan sausage according to its instructions.
Turn the heat down to medium-low and add the flour to the sausage. Mix everything and toast the flour and sausage mixture for 2-3 minutes.
Next mix in the non-dairy milk and spices. Slowly add the liquid to the roux in a couple of rounds. Stirring the mixture making sure it's fully incorporated each time before adding more milk. It will start very thick and almost like dough, but it will thin out as you keep adding the non-dairy milk. (Adding the liquid all at once or too much at once might result in small balls of flour in the gravy.)
Once all the non-dairy milk has been added turn the heat back up to medium-high heat. Stir the gravy until it starts simmering. Let the gravy simmer for around 8-10 minutes stirring occasionally until it has thickened to your desired consistency.
Remove the gravy from the heat, and let it cool for a couple of minutes. This will allow the gravy to thicken some more. Adjust the seasoning and flavor as you desire and then serve.
Serve by cutting a biscuit in half and pouring a scoop or two of the gravy on top. Store any leftover gravy in the fridge for up to 3 days.