Peel the potatoes and dice.
Cut the root end of the leek, remove the top dark green/blue layer, and slice the white body of the leek into one-inch pieces.
Rinse the leek to remove any sand.
In a saucepan, add water, potatoes, leeks, and a pinch of salt. Add the bouillon cube, cover, bring to a boil, then simmer for 15 minutes.
In a skillet, render the fat from the bacon until crispy.
Blend the soup to preferred consistency, adjust seasoning, and add cream if desired.
Drain the crispy bacon, cut into strips, and serve on top of the soup. Drizzle with bacon fat and sprinkle with freshly ground pepper.