No this is not spaghetti, tuna and buns. The spaghetti and tuna are in the buns. This recipe is from Good Housekeeping's Quick 'n' Easy Cook Book from 1958. I know the theme is quick and easy but putting the spaghetti in the bun is just carrying it too far. And personally the idea of tuna with spaghetti has always seemed nasty to me.
Start heating oven to 375 degrees. Cut top from 6 large round hard rolls; scoop out soft part. Spread inside of each roll with soft butter or margarine. Into rolls, spoon 1 can spaghetti in tomato sauce with cheese. Top with 2 cans (2 cups) chunk-style tuna. Sprinkle with 2 tablespoons grated Parmesan cheese. Spoon another can of spaghetti on top. Sprinkle with 2 tablespoon Parmesan, 1 teaspoon dried rosemary. Dot with butter. Bake 15 minutes.