In a large pot over medium heat add the olive oil leeks and salt.

Cook until leeks are soft but not browned stirring often, about 4-5 minutes.

Scoop out about 1/2 cup of leeks and reserve.

Add the chopped garlic and turmeric, give it a good stir and cook another minute.

Now add squash, stock and thyme sprigs, bring to a boil then lower the heat to a simmer.

Simmer until the squash is tender when pierced with a fork.

Remove from heat, discard any tough thyme stems.

Working in batches puree in blender/food processor or hand held returning to a clean pot with each batch.

Bring back to a quick simmer for a few minutes then serve in warmed bowls

Add a good grind of fresh black pepper and top with reserved leeks.