2 cups cold or room temperature mashed potatoes (preferably unseasoned)
1 cup bleached all purpose flour or 1/2 potato flour (starch)
1 cup grated sharp cheddar cheese
2 large scallions, thinly sliced
1/3 cup garlic olive oil
1 large egg, beaten
1 tsp baking powder
2 tsp salt (less for pre-seasoned mashed potatoes)
Fresh ground pepper to taste
Sour cream (optional for serving)
Heat waffle maker. Meanwhile, add all the ingredients to a large bowl, including 1/2 of the scallions. Whisk thoroughly.
Grease the hot waffle iron well. Add 1/3 cup for each waffle. Cook until golden brown on the inside, about 5 minutes per waffle. Serve with a dollop of sour cream, additional scallions, and hot sauce, if desired.