I don't know where it came from, but this is one of my favourite childhood lunches. It likely originated in the maritimes where my parents grew up. Perhaps you don't really want the recipe, it certainly doesn't look all that appealing, but I'll share anyway.
Open a can of Campbell's cream of mushroom soup, put it in a pot, add half a can of milk, and whisk until combined. While waiting for it to heat, make toast. Cut the toast into strips and cut the strips in to squares. (In the old days we would have buttered the toast.) Put squares in the bottom of a bowl, pour half the soup into the bowl and garnish with ketchup in the shape of a favourite letter. Do you have a favourite childhood comfort food you'd like to share?