Providing something hot to eat is the hardest challenge, and although flasks of soup provide scope for spillage and mess, I feel they are worth the risk. This soup - my all-time most-requested- has the bonus, too, of being so simple to make, you can do it while you stumble about the kitchen at breakfast. While you can make it with pesto from a jar, the difference when you use the 'fresh' stuff in a tub that you find in chiller cabinets in the supermarkets is astonishing. I think soups taste better made in a blender rather than a processor, and it's best to use a blender which has a central bit in the top you can remove; this stops pressure building up, which in turn prevents you getting soup all over you or your walls. This would not be a good start to the day.
The quickest way to proceed is to fill a kettle first and put it on to boil. When it's boiled, measure the amount you need into a pan and put on the stove to come back to a boil.
Add the frozen peas, scallions, salt and lime juice and let everything bubble together for 7 minutes.
Discard the scallions and blitz the peas and their liquid with the pesto in a blender.*
Pour into a thermos flask that you've left filled with hot water and then emptied and make sure you screw the top on securely.
*When blending hot liquids: Remove liquid from the heat and allow to cool for at least 5 minutes. Transfer liquid to a blender or food processor and fill it no more than halfway. If using a blender, release one corner of the lid. This prevents the vacuum effect that creates heat explosions. Place a towel over the top of the machine, pulse a few times then process on high speed until smooth.
Recipe courtesy of Nigella Lawson(Copyright 2007, Nigella Express, Hyperion, All Rights Reserved)