Shell the peas if you are using fresh ones. Roughly chop the onion and put it with the peas in a saucepan, add the olive oil and salted water.
When the water is simmering, cook over medium heat for 10 minutes.
Add the mint leaves, pepper, then mix everything finely.
Add the cream and a pinch of pepper.
You can serve hot or cold as you wish, for us it was iced so we could prepare it in advance... and it's delicious!