Season the chicken with salt and pepper. Heat 2 tablespoons oil over medium high heat in a skillet. Add the garlic and ginger and fry for 1 minute, until fragrant. Add the curry paste and fry for another minute.
Turn up the heat to high and add the chicken. Cook until the chicken is browned, and pour in the coconut milk. Bring to a simmer and season with salt to taste. Simmer for 5 minutes and stir in the choy sum. Cook until the choy sum is wilted and stir in the cilantro. Serve over rice.