Heat half the oil in a wok and cook beef in batches over medium high heat until well browned. Remove from wok.
Add remaining oil to wok, add onion and cook until just softened. Reduce heat to medium, add Five Tastes Curry Paste and cook for 1 minute until fragrant. Add potato and sweet potato, stir to coat well in curry paste.
Add coconut milk, coconut and fish sauce, reduce heat to low and simmer uncovered for 15-20 minutes, stirring occasionally until vegetables are just tender.
Return beef and any reserved meat juices to wok and return to the boil. Cook for a further 1-2 minutes.
Spoon curry into serving bowls and top with steamed vegetables, peanuts and basil before serving with rice.