Preheat your frying pan over medium high heat, add 2 tbs of cooking oil.
Pan fry the beef tails on all sides until golden brown. Remove from the frying pan and add to a large pot.
Sauté the vegetables until caramelized. Remove from the pot and set aside.
In the same pan, add tomato paste and fry lightly. Then add diced tomatoes, fish sauce, light soy sauce, dark soy sauce, and boil until slightly thickened.
In the same pan, add tomato paste and fry lightly. Then add diced tomatoes, fish sauce, light soy sauce, dark soy sauce, and boil until slightly thickened.
Toast the spices on a clean pan over medium heat, before adding to the pot.
Add in the sauteed vegetables and 2L of beef stock.
Boil over medium high heat for 3-4 hours. Check and stir every once in a while. Alternatively use a pressure cooker to speed up the cooking time.
Cook the beef tails till soft but not yet falling away from the bone, add in the potatoes and boil for another 15 minutes until potatoes have softened.
Garnish with coriander leaves and serve hot.
