Begin by pouring about one-third of the coconut milk into a wok or pan and then cook it until it starts to separate and an oily sheen begins to appear on the surface.
Next, add the red curry paste and palm sugar or honey to the coconut milk. Mix thoroughly, add the mushrooms, stir to combine, and then cook for one minute.
Stir in the remaining coconut milk, bring the mixture back to the boil, and then add the tofu cubes and green beans. Simmer gently for 4 to 5 minutes before adding the kaffir lime leaves and sliced red chilies.
To serve, spoon the curry into a serving dish and garnish it with some of the cilantro.