Potato and celery soup

Adapted from here. https://www.bbcgoodfood.com/recipes/2998693/creamy-celery-and-potato-soup
Instead of a pure vegetarian soup or the use of chicken stock, I finished up my leftover beef stock and it was splendid!

Ingredients
3 rashes of bacon, finely chopped
6 to 7 celery sticks, chopped
1 sweet potato, cubed
4 potatoes (or carrots as preferred)
½ onion, chopped
750ml beef stock
2 - 3 bay leafs
2 tbsp barley
½ cup milk, full cream (don't use skim or it may split)
1 tbsp olive oil (or butter)

Method
1) Saute the bacon in about 1 tbsp of olive oil until slightly brown and fat has rendered. Add the onions and continue to saute until transparent.
2) Add the chopped celery and saute until slightly softened, followed by the potatoes and briefly fry.
3) Pour in the beef stock, and add the bay leafs and barley.
4) Set to slow cook for anything between ½ hour (until the potatoes are soft) to 2 hours (potatoes disintegrate) according to your liking.
5) Turn off the slow cooker and pour in the milk. Stir to combine.
6) If desired, remove a portion of the soup and veg, and blend the rest with a stick blender. Add back the removed ved. (I didn't do this as I like chunky soups)
6) Serve hot with crusty bread, but I like it cold (after a night in the fridge) in summer.