Heat oil in a non stick wok over high heat. Cook beef (in batches if need be) for 3-4 minutes until browned on all sides. Remove from wok.
Add onion and potato to wok, cook over a medium heat for 5 minutes to soften without browning too much.
Reduce heat and add Five Tastes Curry Paste, cook for 1 minute or until fragrant. Stir in coconut milk and fish sauce, simmer for 5 minutes or until potato is tender.
Return beef to wok, add peanuts and bring back to the boil. Serve garnished with coriander.