Heat the oil in a large wok or saucepan.
Add chopped onion, minced ginger, and garlic. Sauté for a fewminute until it is aromatic.
Add red curry paste. Sauté for 2-3 minutes until oil starts oozing out on the side, and the mixture is aromatic.
Add chicken and the prawns and stir fry for 5 -7 minutes.
Add coconut milk, water or stock, fish sauce, peanut butter, tomato paste and chilli powder if using and the lime zest Mix well and let everything come to a slow boil. Simmer and let it cook for 2-3 minutes.
Add the veggies when the chicken and prawns are almost cooked and the sauce has reduced almost by half (or to the consistency you are looking for). Check the seasoning and add the lime juice.
Cook for another 2 minutes, until the veggies are just cooked but still have a crunch to them.
Garnish with fresh coriander leaves and serve hot over jasmine rice.