Prepare the ingredients: Dice the onion and bacon, cut celery into thin slices, finely chop the garlic. Cut the potatoes into 3/4-inch (2 cm) cubes. Cut the dill pickle into small cubes. Shred the cheese on the large holes of a box grater.
Heat 1 tablespoon of oil in a large pot over medium-high heat. Add the bacon and cook for a couple of minutes, stirring, until browned and crispy. Transfer to a plate with a slotted spoon.
Increase the heat to high. Add the beef in an even layer, don't stir for the first 1-2 minutes letting it brown, then cook, stirring, for a couple of minutes, until it's no longer pink. Break up any clumps of beef. Transfer it with a slotted spoon or spider strainer to a plate.
Add another tablespoon of oil, onions, and celery. Cook for a couple of minutes until softened. Add the garlic, basil, and parsley, cook for 30 seconds.
Stir in flour and cook until incorporated.
Add the beef back to the pot. Add the broth, milk, heavy cream, and potatoes. Bring to a simmer and cook over the lowest heat for 10-15 minutes or until the potatoes are soft. Make sure the soup is not boiling rapidly.
Add the cheese in 3 additions, stirring after each portion added until it's melted.
Add the chopped pickles and pickle juice, if using.
Season the soup with salt and pepper, to taste.
Garnish with cooked crumbled bacon and thinly sliced green onions.