Heat the oil in a wok or large pan over medium-high heat. Sauté the onion for 2 minutes, then add the garlic, hot chiles and ginger. Cook another minute or two.
Pour in the coconut milk, then add the fish sauce and curry paste. Stir well. Bring to a simmer and add the bell pepper and citrus leaves, if using. Simmer 10 minutes.
Stir in the thinly sliced meat and peanuts, and let this cook until the meat is done, maybe 5 more minutes. Mix in the chopped herbs and serve with jasmine rice.