Place the leeks and onion into the Thermomix bowl and chop on Speed 6, 5 seconds. Scrape down the sides of the bowl.
Add the butter and minced garlic and saute on 100 degrees, Speed 1, 5 minutes.
Add the potatoes and cook on 100 degrees, Speed 1, 5 minutes.
Add the chicken stock, salt and pepper and cook on 100 degrees, Speed 2, 20 minutes (with the MC removed but the rice bowl sitting on top to stop any splashes). Allow the soup to cool slightly.
Very slowly increase to Speed 6 to puree the soup, 30 seconds.
Add the cooking cream and heat for a further 3 minutes, 100 degrees, Speed 2.
Meanwhile cook the streaky bacon in a frying pan until crispy.
Serve the soup with the crispy bacon and hot buttered bread.