- 2 tablespoons olive oil
- 2 tablespoons butter
- 2 onions, sliced
- 1 teaspoon minced garlic
- 1 teaspoon chopped fresh thyme
- 2 1/2 cups leftover mashed potatoes, warmed
- Salt and pepper, to taste
- 2/3 to 1 cup milk, or as needed
- 2 eggs, beaten
- 1 cup all-purpose flour
- 2 teaspoons baking powder
Melt oil and butter over medium heat in a saucepan. Add onions and cook, stirring often, until caramelized, 15 to 20 minutes. Stir in garlic and thyme and cook for 1 minute.
In a large bowl, combine potatoes, onion mixture, salt and pepper. Add enough milk to make potatoes smooth and looser than those normally served as a side dish. Beat in eggs, then fold in flour and baking powder.
Preheat a waffle iron and spray or brush with oil, if needed.
Add about 1/2 cup batter to the waffle iron and spread evenly almost to the edge with a spatula. Close the lid and cook until brown and crisp. Serve immediately or keep warm in a single layer in a 200° F oven until ready to eat.