Put one-third of coconut milk into wok. Cook until an oily sheen appears on the surface.

Add curry paste, fish sauce and coconut milk. Mix thoroughly. Add the button mushrooms. Stir well and cook over medium heat for 1 minute. Stir the rest of the coconut milk and bring back to boil. Add French beans and tofu cubes. Simmer gently for another 4-5 minutes. Stir in kaffir lime leaves and red chillies.

Garnish with coriander sprigs.