While the pesto can be bought in a jar, Nigella Lawson promises that the fresh version "you can find in chiller cabinets in the supermarkets" will taste so much better.

The chef said the difference between jar-bought pesto and the fresh version is "astonishing".

In her cookbook Nigella Express, she penned her fresh pea and pesto soup recipe that is best made in a blender.

Nigella Lawson explained: "I think soup tastes better made in a blender rather than a food processor.

"And it's best to use a blender which has a central plug in the lid that you can remove to stop the pressure building up — which, in turn, prevents you getting soup all over you or your walls."

Pea and pesto soup

Serves: two people

Ingredients

• 375g frozen peas
• Two spring onions (trimmed but whole)
• One tsp Maldon salt
• Half tsp fresh lime juice
• Four tbsp pesto
• Two tbsp pine nuts

Method

Fill a kettle and put it on to boil. Once it's boiled, measure 750ml of boiled water into a pan, and put on the hob to come back to the boil.

Add the frozen peas, spring onions, salt and lime juice to the pan and let everything bubble together for seven minutes.

Discard the spring onions and blitz the peas and the liquid with the pesto in a blender.

Pour the liquidised soup back into the pan and keep warm over a gentle heat until you are ready to ladle into bowls.

Meanwhile, tip the pine nuts into a small frying pan, and toast over a medium heat until they begin to colour.

Once the soup is served into bowls, sprinkle the pine nuts over each bowl of soup.