Heat oil over medium heat. Add onions, garlic. Cook about 5 minutes.
Add Seasoning Mix A. Cook until brown but not burned - about 8 minutes.
Add stock, Worcestershire, chili paste. Bring to fast simmer, stirring often. Cook 8 minutes.
Add tomato, bring to boil over medium heat. Add sugar and scallion.
Simmer for 40 minutes, stirring occasionally. DO NOT BURN.