In a large cold soup pot, place the bacon pieces, and turn the heat on to medium high and render the pieces down. Stir occasionally.
When the bacon is almost crisp, turn the heat down to medium, and add the onion.
Stir and saute the onion. When the onion has softened, add the garlic and saute for a couple minutes.
Add the beans, stir to mix, then add the stock, potato (mashed up), dried mustard, dried oregano, and white pepper.
Very lightly salt at this point.
Let simmer for half an hour, then using a hand blender, blend to your desired consistency.
Let simmer for another half hour, then taste for any further salt seasoning.
Notes
I like some texture in a bean and bacon soup, so only use the hand blender until about half of the soup is smooth. You do not need to add the potato. I used it as a thickener and to use up what was in my fridge.