Heat the oil in a large saucepan over medium high. When hot, sauté the onion until translucent, but avoid browning it. Add the garlic and sauté for about a minute until fragrant, then add the potatoes along with five cups of water. Bring to a boil over high heat, then reduce heat and simmer for 30 minutes.
Add the dill and simmer for 15 minutes more.
While the soup is cooking, add three pieces of bacon to a cold skillet, and cook over medium heat until crispy. Transfer to paper towels to drain.
Once the soup is cooked, transfer half of the soup to a blender and puree, then return the puree to the pan. Alternatively, use a hand blender directly in the pan, but make sure to leave lots of chunks of potato. Season with salt and pepper to taste.
Serve in warm bowls with bacon crumbled on top.