Heat a large stockpot over medium high heat and add the chopped bacon. Cook, stirring often, until the bacon is crisp and the fat is rendered. Remove the bacon with a slotted spoon and drain on paper towels. Set aside to use as a garnish. Reserve the fat in the pan.

Add the onion, garlic and rosemary to the bacon fat and sauté until the onion is tender and translucent.

Add the potato cubes and the stock and bring to a boil. Reduce heat, cover partially and simmer until the potatoes are tender, about 20 minutes.

When the potatoes are tender, puree the soup using an immersion blender. If you don't have an immersion blender, remove the soup from the heat and let cool. Blend in batches in a blender, making sure to vent the steam. This is a VERY important step so make sure you allow the steam to escape or you might have very hot soup all over your kitchen.

When the soup is pureed, stir in the sour cream. Taste for seasoning and add salt and pepper to taste.

Ladle the soup into bowls and garnish with the reserved bacon, truffle cheddar, dill, and green onions. Enjoy!