Heat a large dutch oven or other large pot over medium heat.
Add bacon pieces and cook unitl bacon renders its fat.
While bacon is cooking, wash and cut up leeks. Discard tough green part and cut white part lengthwise into quarters, then cut into ¼ inch pieces.
Add leeks to the pot and cook until they soften, about 7-8 minutes.
While leeks are cooking, peel and dice potatoes into 1 inch sized chunks.
Once leeks are tender, add minced garlic and cook until fragrant, about 1 minute.
Add potatoes and chicken broth to the pot. Increase heat to medium high and bring mixture to a boil.
Add ¼ teaspoon pepper and ½ teaspoon salt. Stir to combine.
Once broth comes to a boil, cover and reduce heat to low.
Simmer soup over low heat stirring occasionally, until potatoes are soft, about 45 - 60 minutes.
Once potatoes are soft, use an emmersion blender to carefully blend soup until thick and smooth.
Add additional chicken broth or a little white wine to thin soup if it's too thick.
Taste and add salt & pepper as needed to taste.
Serve with a dollop of sour cream, a sprinkle of grated Parmesan cheese and chopped green onions.