Preheat the waffle iron. Set it to medium-high.
A hot iron is essential for a crisp crust.
Mix the dry ingredients. In a large bowl, whisk 1 1/2 cups flour, 1/4 cup cornstarch, 2 teaspoons baking powder, 1 teaspoon kosher salt, 1/2 teaspoon black pepper, and 1/2 teaspoon garlic powder.
Whisk the wet ingredients. In a separate bowl or large measuring cup, whisk 1 1/2 cups buttermilk (or milk), 2 large eggs, and 4 tablespoons melted butter or oil.
Combine gently. Pour the wet mixture into the dry, stirring just until a few streaks of flour remain. Don’t overmix; a few small lumps are fine.
Fold in the flavor. Add 1 cup shredded cheese, 2–3 tablespoons chopped fresh herbs, and 2 sliced scallions. Fold until evenly distributed.
If using add-ins like bacon or spinach, fold them in now.
Rest the batter. Let it sit for 5 minutes while the iron fully heats. This helps the gluten relax and the starch hydrate.
Grease the iron lightly. Use a quick spray or brush with oil for insurance, even if it’s nonstick.
Cook the waffles. Add enough batter to cover the grid without overflowing (usually 1/2 to 2/3 cup per waffle). Close the lid and cook until deeply golden and crisp, about 4–6 minutes depending on your iron.
Keep them crisp. Transfer finished waffles to a wire rack set over a sheet pan in a 200°F (95°C) oven while you cook the rest.
Serve hot with savory toppings. Great with a fried egg, hot honey, Greek yogurt, smoked salmon, avocado, or a simple arugula salad.