Remove the tough outer layer of the leek. Cut the ends off the leek and most of the green stalk then cut the leeks in half and rinse. Then slice them into 1/4" pieces.
Separate the broccoli florets from the stalks and break up into small pieces
Let the soup cool down a bit. Remove the bay leaf with a slotted spoon. Then blend the mixture with an immersion blender or in a blender.
Once it's a smooth soup put your pot back on the stove on medium-high heat and then add the remaining potatoes, broccoli, and leeks. Bring to a boil and then let simmer for 15-20 minutes until done.
Topping
While the soup is cooking, cook the bacon in a frying pan until crispy, then transfer it to a plate with a paper towel. Reserve 1 tbsp., of bacon grease. When the bacon is cooled, crumble it up.
Combine the bacon bits, 1 tbsp grease, and 1/2 cup of bread crumbs.
Serve the soup with the bacon topping and some grated cheddar cheese, if desired.