Cook the peas in boiling, slightly salted water until tender, then drain and tip into a blender, adding 1 tablespoon curry paste and the creme fraiche or sour cream. Season to taste with salt and perhaps add more curry paste, depending on how strong it is.
Heat the oil and butter in a frying pan until foamy, and then fry the scallops for 2 minutes a side. If you are using big scallops then it is sometimes easier to cut them in half across.
When they are cooked, they will have just lost their raw look in the middle and be lusciously tender, while golden and almost caramelised on the outside.
Lift the scallops onto two warmed plates and then deglaze the hot pan by squeezing in the lime juice. Stir to mix well and pick up every scrap of flavour, and then pour over the scallops on each plate.
Dish up the pea puree alongside the scallops, and sprinkle with the chopped cilantro or Thai basil. Serve with another wedge of lime if you feel like it.
Make Ahead Notes: The pea puree can be made 2 to 3 hours ahead. Drain peas and immediately rinse with plenty of cold water. Puree when cold with 1 tablespoon of the curry paste and creme fraiche or sour cream. Put in a bowl, cover and leave in a cool place or refrigerator. Reheat gently in a saucepan, taste and adjust seasoning before serving. If using sour cream, make sure the puree doesn't boil, otherwise it will turn grainy.
From NIGELLA KITCHEN by Nigella Lawson. Copyright 2010 Nigella Lawson. Published by Hyperion. Available wherever books are sold. All Rights Reserved.