Prepare mushroom cream sauce: Melt butter and mix in flour to form a paste. Slowly stir in milk, bring to the boil. Add mushroom and cook for 1 to 2 minutes.

• 预备忌廉蘑菇汁：牛油慢火煮溶，拌入面粉成糊状。徐徐拌入奶煮滚。放入蘑菇煮1至2分钟。