Feel free to substitute yellow cheddar for a fun color change in this soup. Slideshow: More Warming Soup Recipes
In a large heavy pot over medium heat, cook the bacon, turning occasionally, until crisp, about 8 minutes. Transfer the bacon to paper towels to drain, reserving the fat in the pot. Crumble the bacon.
Stir the onions, garlic, 3/4 teaspoon salt, and 1/2 teaspoon pepper into the bacon fat in the pot and cook, stirring occasionally, until golden, 8 to 10 minutes. Peel and dice the potatoes. Stir in the potatoes and stock bring to a gentle boil. Cook the soup, stirring occasionally, until the potatoes are very soft and starting to fall apart, 45 minutes to 1 hour. Stir in the cheese and remove from the heat. In a blender, puree the soup in batches, until smooth. Season the soup with salt and pepper to taste and serve topped with the crumbled bacon and additional cheese.