Angela Hartnett's Courgette and Mint Soup

This soup is perfect with sourdough bread and goat's cheese. Eat it chilled on hot summer days, or if the weather is not so good, just serve it warm.
This fresh soup works equally well warm or cold. I love it chilled on a hot afternoon. Use those courgettes at the bottom of your fridge that are getting a bit soft.Serves 3-44 tbsp olive oil
Generous knob of butter
1 small onion, chopped
2 small courgettes, thinly sliced
Pinch of salt
300g frozen peas
500ml vegetable stock (top up with water to cover if necessary)
Handful of mint, torn
Handful of watercress, torn
50g spreadable goat's cheese
8 small pieces of toasted sourdough breadPut half the oil and all the butter into a pan on a medium heat. Saute the onion until soft, but without colour, then add the courgettes, season and cook for about five minutes.Stir in the peas, add the stock, boil, then simmer for a few minutes. Check the seasoning, blend the mixture, thinning it with water if necessary.If you want the soup cold, pour it into a bowl over some ice to chill quickly, then refrigerate. Chill your bowls before serving the soup, then garnish with the mint, watercress and a little olive oil.Spread the goat's cheese on to the sourdough toast for croutons and serve on the side.• Angela Hartnett is chef patron at Murano restaurant and consults at the Whitechapel Gallery and Dining Room, London. Twitter.com/angelahartnett
Angela Hartnett's courgette and mint soup. Photograph: Linda Nylind for the Guardian