Heat oil in a saute pan. Add chicken and cook quickly over a high heat until lightly browned. Add chilli, curry paste, coconut milk and sugar. Bring to the boil, simmer for 3-4 minutes. Add potatoes and peas, cover and simmer for 10-12 minutes until potatoes are tender. Add coriander, lime juice and season to taste. Place the rice or noodles into serving bowls, top with the Thai green curry and a sprinkle of spring onion. Serve with crusty bread.