Here is an easy one.  And you can make one of two ways, both delicious. Boil potatoes and make your favorite mashed potatoes.  I boiled 6 russet potatoes, peeled, until tender.  I like to throw some minced garlic right in the water while they boil for a good flavor.  Drain water, add a splash of non dairy milk, and hand mash until creamy, add s&p to taste.  Then place in the center of your preheated hot waffle iron, and cook until crispy, mine took about 5-7 minutes.   Yummo!  I like them plain, but you could also enjoy them with ketchup, salsa, or your favorite non dairy sour cream..   6 medium size potatoes makes about 3 good size waffles.  

6 med russet potatoes, peeled and chopped into pieces
1 T minced garlic
Deep pan of water
S&P to taste
1/4 to 1/2 cup veg broth

Boil russet potatoes in water with the garlic for about 20-25 min until very tender.  Drain then use hand masher adding splashes of the veg broth only as needed, I kept it a pretty stiff mashed potatoes.  Put approx. 1 cup of mixture in your waffle maker, it will likely take longer than you are used to, they cook slower than regular waffles and you want them to be good and crispy before you try removing them or they will stick. 

Another equally delicious alternative, if you have no mashed potatoes and don't feel like making them... you can simply make hash brown waffles.  Just take a bag of frozen hash browns, (check label, make sure it is only potatoes, usually the store brand) let it thaw in the fridge overnight, then pour onto your waffle maker  (approx 6 oz for my wafflemaker) and cook for about 10 min or until crispy, they are done when they release easily from the wafflemaker and they are golden brown.  If you open the waffle maker too soon and they are stuck, put back in for a few minutes..
Depending on your waffle maker, you may or may not need to add an oil spray to prevent sticking.  Ceramic ones generally do not stick at all, non stick may need a slight spray.