Summer squash soup

Serves 4

90g unsalted butter, cut into pieces
1 medium onion, halved lengthwise and thinly sliced
½tsp salt
1kg yellow summer squash, halved and thinly sliced
2 carrots, thinly sliced
250g potato, peeled, halved,
1ltr chicken stock

1. Melt the butter in a wide, heavy bottomed pan over a low to medium heat, add the onion and ½tsp salt, stirring, until softened (but not browned) for about 8 minutes.

2. Add the squash, carrots, potato, and stock and bring to a boil. Reduce heat, then simmer, partially covered, until vegetables are very tender, about 20 minutes.

3. Remove from heat and cool, uncovered, for 10 minutes. Purée with a stick blender until smooth. Thin with water if desired; simmer 3 minutes. Adjust seasoning is required then serve immediately.

(adapted from http://www.epicurious.com/recipes/food/views/Summer-Squash-Soup-with-Parsley-Mint-Pistou-235736)