Brown the vegetables in butter. Add flour to make a brown roux. 将蔬菜在黄油中炒至焦黄，加入面粉做成棕色面糊。
Add stock, tomato sauce and sachet. Simmer for about 1 hour. 加入牛骨高汤，蕃茄沙司和香料袋。慢火煮约1小时。
Strain through a chinois and season to taste. 用细目滤斗过滤后用盐和黑椒调味。
*Pan-seared skirt steak with brown sauce and mushroom & onion. 用酱汁在盘中浇一个圆形，铺上蘑菇炒洋葱，再放上几块切好的煎牛排。