Heat sunflower oil in a large preheated wok or saucepan.
Thinly slice the chicken. Add the chicken to the pan and stir fry for 5 minutes.
Add the garlic, curry paste, ginger, tamarind and lime leaves to the pan and stir fry about a minute more.
Peel and dice the sweet potato. Add the coconut milk and sweet potato to the mixture in the pan and bring to a boil. Allow to bubble over a medium heat for 20 minutes, or until juices start to thicken and reduce.
Add the cherry tomatoes and cilantro to the curry and cook for a further 5 minutes, stirring occasionally. Transfer to serving plates and serve hot with cooked rice.