In a Dutch oven or large soup pot, cook the diced beef bacon over medium heat until crisp. Remove with a slotted spoon and set aside on paper towels, reserving about 1-2 tablespoons of drippings in the pot.
Increase heat to medium-high. Add the cubed beef chuck to the pot and sear until browned on all sides, about 5-7 minutes. Remove beef and set aside with the bacon.
Add the butter to the pot. Once melted, add the chopped onion and sauté until tender and translucent, about 5 minutes.
Stir in the flour, salt, and black pepper. Cook for 1-2 minutes, stirring constantly to remove the raw flour taste.
Gradually whisk in the water (or beef broth), half-and-half, and evaporated milk. Bring the mixture to a gentle boil, stirring occasionally to ensure the base is smooth and thickened.
Reduce heat to low. Add the potatoes and the browned beef chuck back into the pot. Cover and simmer gently for 20-25 minutes, or until the potatoes are tender and the beef is cooked through.
Stir in the reserved crisp beef bacon just before serving (save some for garnish if desired).
Ladle into bowls and garnish with fresh minced parsley.