Boil the beef briskets in a pot with water, salt and onion. Remove the scum and cook until tender.
Transfer the meat to a bowl and set aside. Don't throw away the soup stock and set aside also.
In another pot or deep pan, saute the ginger, garlic and onion.
Put the boiled meat and stir fry for a few minutes and season with soy sauce, brown sugar, star anise and pepper.
Pour about 2 cups of soup stock. Simmer for about 5 minutes.
Add the cornstarch mixed with a little water to the pot to thicken the sauce.
Season with sesame oil and transfer to a bowl. Garnish with fried toasted garlic.
Serve with garlic rice and soup stock garnished with scallion.