Chilled summer garden soup with nasturtium pesto by Anna Hedworth

I owe Diana Henry a drink, because this is a tweaked version of her recipe that I decided to make on television as part of Cook House, appearing on what turned out to be a beautiful programme called Hidden Restaurants. I cooked this in the kitchen with Michel Roux Jnr, while shaking in my boots, but it turned out to be the best boost to business we ever had. I will therefore always remember this soup. We topped it with a chunky nasturtium pesto that Michel made – I should probably buy him a drink, too, while I’m at the bar.

Serves 4
cucumber 1, peeled and chopped
very fresh young courgettes 2, chopped
walnuts 50g
blanched almonds 50g
garlic 4 cloves
spring onions 3
chives 3 tbsp, chopped
mint 3 tbsp, chopped
dill 3 tbsp, chopped
tarragon 2 tbsp, chopped
chilli flakes a pinch
stale sourdough bread 50g, crusts removed
weak chicken stock 250ml
live full-fat natural yoghurt 200g
extra virgin olive oil 100ml
lemon juice of ½
white balsamic vinegar 2 tbsp

For the nasturtium and pumpkin seed pesto (makes 200ml)
garlic 1 clove
salt and pepper a pinch
olive oil a splash, to start, then more to desired consistency
nasturtium leaves 25g
mint leaves 6
nasturtium seed pods 10
pumpkin seeds 25g, toasted

To make the pesto, place all of the ingredients in a small blender and blitz. Check the consistency and add more olive oil depending on if you want a thick or thin pesto. Keep it chunky to top stews and soups, or blend until very fine for pasta and salads.

To make the soup, put all the ingredients into a blender and blend until smooth. You may have to do this in batches, depending on the size of your blender. Check the seasoning, it does not need much salt or pepper, just a little, but it may benefit from a tiny bit more vinegar. Chill the soup thoroughly before serving.

Serve the soup with a drizzle of the fresh peppery nasturtium and pumpkin seed pesto.