You can omit the potato and, if you like, use rice instead. Swiss Chard would be nice in it and I added some frozen chopped kale. I used frozen broccoli. Tracy omits the peas. In my mind, the secrets to this – for vibrant colour and taste as well as nutrients – are the parsley and watercress. This is good served hot, at room temperature or cold. I like to swirl a little plain yogurt in each bowl for garnish.

1 medium leek, white and light-green parts only, halved lengthwise, thinly sliced
½ medium head broccoli, florets only
1 small cucumber, peeled, sliced
1½ cups frozen tiny peas, defrosted
1 or 2 medium potatoes, peeled, sliced
1 small bunch parsley, leaves only
1 medium bunch watercress, leaves only
½ small green cabbage, cored, shredded
6 cups chicken or vegetable stock
5 tsp kosher salt, or to taste
1 tsp white wine vinegar
20 basil leaves, shredded
Lots of freshly ground black pepper

In large saucepan, combine leek, broccoli, cucumber, peas, potatoes, parsley, watercress, cabbage and stock. Bring to a boil. Lower heat, partially cover and simmer until all vegetables are tender, about 20 minutes.

In batches, puree mixture in food processor, blender or through food mill. Let cool. Stir in basil and pepper. Bring to a boil. Lower the heat, and simmer for 1 minute.

Makes about 8 servings.