Pre-heat oven to 350-F degrees, cut a thin cross
on the potato skins, and bake potatoes for 1 hour,
or until thoroughly done.
Halve the baked potatoes when they are cool enough to handle. Scoop out the baked potato meat, leaving 4 of the potato halves intact for stuffing and re-baking.
In a large mixing bowl, combine the cooked potato with the tomatoes, scallions, sour cream, and tuna. Season to taste with salt and pepper after all ingredients have been thoroughly blended.
Stuff the reserved potato halves with the tuna mixture. Either re-heat them before serving now, or refrigerate to enjoy at a later meal.