1. Heat the olive oil (1 tbsp) in a frying pan over medium heat and fry garlic until fragrant. Add onion, celery and cook until the onion is wilted. Add mushroom, minced beef, and continue stir frying till no longer pink.
2. Add all "A" ingredients and stir the sauce constantly till it comes to a boil. Then reduce the heat to low, simmer for about 30 to 40 mins with a lid.