Ingredients
4 Tbsp butter
1 lb white mushrooms, sliced
3 rounded Tbsp flour
1 quart beef stock
¼ tsp thyme
salt
black pepper
Directions
Melt butter in a 4-quart saucepan over medium heat. Add mushrooms and a pinch of salt, stir occasionally, and simmer for about 20 minutes. Mushrooms will reduce and most liquid will have evaporated. Sauté until browned.
Add flour to the mushrooms, stir to combine, and sauté for about 5 minutes. Slowly stir in beef stock and increase heat to medium-high, bring to a simmer. Add pepper and thyme then reduce heat to medium-low. Simmer for about 30 minutes, skimming foam as needed, then season to taste.