Heat the oil in a medium saucepan. Tip
in the onion and ginger, then cook for a few
mins until softened. Stir in the curry paste,
then cook for 1 min more. Pour over the
chopped tomatoes and coconut cream.
Bring to the boil, then leave to simmer for
5 mins, adding a little boiling water if the
mixture gets too thick.
Tip in the prawns, then cook for 5-10 mins
more, depending on how large they are.
Serve alongside some plain rice and sprinkle
with a little chopped coriander, if you like.