Place the butter in a large pot and place over a medium high heat.
Once the butter has melted, add the garlic, onion, potato, and leek. Fry for 2 minutes until aromatic, then cover and sweat for 8 minutes.
Add the stock, carrots, celery, lower the heat and simmer for about 20 minutes or until the vegetables are tender when you insert a fork.
Season with a salt and pepper to taste
Blitz with a food processor or a hand blender to get a thick, creamy and smooth soup.
Serve with a dollop of fresh cream and a sprig of parsley. The soup tastes great accompanied with freshly baked Irish soda bread or Irish brown bread.