In a large saucepan over medium-low heat, heat the butter and olive oil. Add the leeks, onion and garlic and cook until translucent and soft.
Add the potatoes, chicken stock and season with salt and pepper. Bring to a boil and then simmer for 15 minutes or until the potatoes are very soft.
Use a hand-held blender or food processor to puree the soup until smooth and creamy.
Add the cooking cream and bring to a low simmer for a further 2-3 minutes or until heated through.
Meanwhile cook the streaky bacon in a frying pan until crispy and set aside.
Serve the soup with the crispy bacon and hot buttered bread.
Thermomix Instructions - Click the link in the notes section below for the Thermomix recipe.