Cook vegetarian hot dogs per instructions on package, let cool. Chop or mince hot dogs to your liking and mix in mayo, along with any other condiment(s) of your choice (mustard, relish, ketchup, onions, olives, etc.). Spread on whatever kind of bread that you like, and enjoy!
This is how I recently made mine. I cooked and chopped 1 veggie dog. Then I put it in a mini food processor with mayonnaise and a chopped up dill pickle slice which had been rolled up in a bit of paper towel to blot out the excess moisture. I then buttered 2 slices of toasted Italian bread and made my sandwich. Very good!