For the Salisbury steaks: In a large bowl, add the chuck, breadcrumbs, mustard, ketchup, onion pulp, salt and a few hefty grinds of black pepper and gently mix to combine. Divide into fourths and make four 1/2- to 3/4-inch-thick oval burgers; set aside.
In a large pan with straight sides on medium heat, add the bacon and cook until crisp, 8 to 10 minutes. Remove to a paper towel-lined plate, leaving the bacon fat in the pan. Cool the bacon, then chop.
In the same pan, turn the heat to high and add the formed burgers. Sear on one side for a few minutes, then remove to a plate.
For the sauce: In the same pan, add the beef stock and scrape up any bits. Add the heavy cream and American cheese and stir. Bring to a boil. Stir in the noodles. Nestle the burgers into the noodles and sauce, cover, lower the heat to a simmer and cook until the burgers are done and the noodles are cooked, about 10 minutes. Stir in the parsley and bacon.
Serve family style or place a burger on a plate with noodles and serve topped with sauce.