Break up the beef and drop loosely in a large bowl. Sprinkle the breadcrumbs evenly over the beef.
In a medium bowl, add the tomatoes, soup mix and Parmesan. Mix and mash up any large chunks of tomatoes using a potato masher. Taste and season with salt and pepper if necessary (the mix packet contains lots of seasoning, so you probably won't need to). Add the egg and stir.
Pour all but 1/2 cup of the flavor base (tomato mixture) over the top of the beef. Using your less dominant hand with your fingers spread out like a pitchfork, gently mix and fold everything together, turning the bowl with your free hand, until just combined. Don't over-mix!
Form the mixture into the shape of a loaf on a parchment-lined baking sheet or press gently into a meatloaf pan. Top the loaf with the remaining flavor base. Cook until the internal temperature is 155 degrees F, 50 to 65 minutes. Remove and gently cover with aluminum foil for 10 minutes to allow the ambient heat to bring it to 160 degrees F before slicing and serving.