Melt the butter in a large pot and gently cook the leeks and garlic for 4-5 minutes or until softened. Add the mushrooms and thyme and cook on high for 2-3 minutes.
Pour over the stock and cook for 5 minutes.
Remove from the heat
carefully pour into a food processor and blend until smooth. Alternatively
keep in the pot and use a stick blender to blitz until smooth.
