Been around since '35, and "boxes of soup," to me, would mean dehydrated soup, not boxes of cans.
In case anyone wondered, the dehydrated soups can be better, because they need SO mcuh more fixens added to them to maske them decent, whereas with the cans--it's sort of: what you get is what you serve. Dry soup cries out for imaginatrion, whereas canned soup says take it easy and serve what you bought.
As for En nis, I don't think he would be much of a gourmet cook, so dried soup would probably be pretty dull. Back in '63, there were few if any interesti9ng casnned soups either--if you ask me, there were damnerd few interesting canned ANYTHINGS...