Tip in the shallots, chilli, garlic and ginger and fry for 2 minutes. Add the Thai paste and sweet potato and stir until well combined. Add the coconut milk and lemongrass and stir well.

Lower heat and cook for 40 minutes. Then drain and set aside. Place a tablespoon of vegetable oil in a wok and place over a high heat. When the oil is hot, lower the heat to medium, and stir-fry the ...