Dice the potatoes and onions.
Melt butter in a pot and sauté the onions.
Add the potatoes and sauté for a bit longer.
Pour in the broth and boil until the ingredients are cooked.
Blend the ingredients smoothly with a hand blender.
Add milk and simmer while stirring well.
Season with salt and pepper.
Serve on a plate and garnish with parsley.