1. Bring wok to medium high heat. Add 2 tbsp of oil and fry Tom Yum paste until water evaporates.

2. Add beef slices and fry for 2 mins, coating well with Tom Yum paste. Add a pinch of salt and asam water. Cook until medium rare to medium in doneness. Dish out cooked beef into a bowl.

Without turning off the heat, drizzle a fresh tablespoon of oil into the wok and fry lemongrass and galangal. Add garlic, chilies and fry shallots till fragrant.

4. Drop in the white button mushrooms and fry to a slight char (2-3 mins).

5. Add a teaspoon of Nam Prik Pao and toss Kai lan and lime leaves with everything. Stir-fry for a min before adding rice

6. Increase heat slightly and fry rice until crisp. Season with fish sauce and coat well with other flavors.

7. Season further with sauce from fried beef, adding slowly by the spoonfuls, careful not to make rice soggy.

8. Now return the beef slices into wok and all of sauce if desired. Squeeze a whole lime and sprinkle salt to taste.

Dish out into plates before beef overcooks and garnish with a wedge of lime and optionally with shredded lime leaves.