1.Blend or process nuts until chopped finely. Transfer to small bowl.
2.Blend or process onion, garlic, ginger, lemon grass, chilli, rind and coriander until chopped finely.
3.Heat oils in medium saucepan; cook onion mixture, stirring, over low heat, about 10 minutes or until fragrant. Add cumin and turmeric; cook, stirring, 1 minute. Stir in nuts, coconut milk, sauce, tamarind and sugar; bring to a boil. Reduce heat; simmer, uncovered, 5 minutes.