Preheat the waffle iron.
Melt the butter in a small pot.
2 tablespoons unsalted butter, melted
In a medium bowl, mix the dry ingredients (flour, cornstarch, baking soda, and salt).
¾ cup (94 grams or 3.3 ounces) all purpose flour, ¼ cup (32 grams or 1.1 ounces) cornstarch, ¼ teaspoon salt, 1 teaspoons baking soda
Mix the liquid ingredients. If you've measured your buttermilk in a 2 cup measuring cup, just add the egg and butter to the measuring cup and whisk.
1 large egg, ⅞ cup (210 milliliters) buttermilk, 2 tablespoons unsalted butter, melted
Add the liquid ingredients to the dry and stir until just combined.
Add the cheese and ham and mix in.
3 ounces ham, chopped, 3½ ounces (⅞ cup) grated gruyere, swiss, or cheddar cheese
Follow your waffle iron's instructions for making the waffles.