Cut 250 grams of radish (about 2 cups) into pieces 1 inch x 1 inch and ⅛ inch thick (2.5 cm x 2.5 cm and 0.3 cm thick). Put into a pot.
Cut 250 grams of beef brisket into bite sized chunks and put it into the pot.
Add 1 tbs hot pepper flakes, 2 tbs fish sauce, 1 tbs toasted sesame oil, 1 ts kosher salt, 2 cloves of minced garlic. Mix it well with a spoon.
Add 5 cups of water. Bring to a boil over high or medium high heat with the lid closed for about 20 minutes.
Tip: when the soup starts boiling (After 10-13 minutes), skim off any fat or foam that floats to the surface of the soup.
Lower the heat over medium heat and cook for another 30 minutes.
Chop 3 stalks of green onions and add it to the soup.
1 minute later, turn off the heat. The soup is done! Serve with rice.
