In a pan with high sides, over medium heat melt the butter
Add the salt, pepper, thyme and mushrooms and combine with a whisk
Add the flour and stir to combine
Once you have incorporated your flour, spices, mushrooms and butter together, add one cup of milk and continue whisking
Once the mixture has thickened add the remaining milk and whisk while continuing to cook over medium heat until the gravy is thickened.
If the mixture is too thick simply add 2 T of milk and whisk until thinned.
Remove from the heat and enjoy!