Combine all ingreds [except hot dog buns!] in a bowl. Mix lightly.
Split buns, and fill them with the tuna mixture.
If you buy your hot dog buns in a box, return the filled buns to the box in which they came. OR, wrap each filled bun in aluminum foil. Wrap kind of loosely, so the filling doesn't stick to the foil. You can wrap them all in one huge piece of foil, if that's the way you prefer to do it.
Place boxed or foil-wrapped buns in the oven at 250°. Cook for about 30 minutes, until filling is hot, and the cheese is bubbly and melted. Serve right away, while hot.