Melt the butter in a dutch oven over medium-high heat. Add the mushrooms and cook, stirring occasionally, until mushrooms are lightly browned, about 10 minutes.
Stir in the flour, onion powder, garlic powder, thyme, 1 tsp salt, and ¼ tsp pepper until well combined.
Stir in the water and bring to a boil.
Reduce heat to medium-low and simmer, stirring occasionally, until thickened, about 15 minutes.
Season with additional salt & pepper if necessary.
