NOTE: If using fresh potatoes, peel, cube, and boil for 7-8 minutes. Remove from heat and set aside. Leave in water, you'll need some of that later.
Cut up bacon strips into chunks and fry till crispy in a heavy Dutch oven. Remove and set aside. When cooled, crumble.
Add onions and cook until translucent. Remove and set aside.
NOTE: If using fresh ground beef, add to the pan and cook until no longer pink. Remove and set aside.
Drain bacon grease, reserving 4 Tbsp and return to Dutch oven.
Whisk in flour and cook until browned.
Add the beef bouillon and whisk in.
Add milk and whisk until smooth. Continue to cook until thick, 2 - 3 minutes.
Return the onions and 3/4 of the cooked bacon to the pan, reserving the last 1/4 for garnishing if desired.
Add the ground meat, potatoes, and mushrooms with the liquid from the jars. Season to taste. Stir well and cook until heated through.
NOTE: if using freshly cooked potatoes, add enough of the potato water to give the desired consistency.
Adjust thickness by adding milk, if necessary.