1. Clean the winter melon and peel off the skin. Cut into 4 pieces (length-wise) and remove the core. Then slice (width-wise) into pieces until finish all (1" thick).
2. Heat oil in a wok over medium heat. Stir fry kang kua curry paste with coconut milk (1 cup). Fry until aromatic and the oil has clearly separated from the coconut milk. Add chicken and fry until nearly cooked. Then add the rest of coconut milk (2 cups)
3. Keep stirring until the winter melons are cooked. Then add torn kaffir lime leaves and holy basil leaves. Season with tamarind concentrate, sugar and fish sauce. Remove from heat.
4. Transfer to a serving bowl. Garnish on top with sliced red chilies. Serve immediately with hot steamed rice.