In a large bowl, combine the flour, cheddar (if using), rosemary, baking powder and salt.
In another bowl, whisk together the milk, egg and oil. Add the wet ingredients to the dry ingredients and whisk just until combined.
Cook the batter in a preheated waffle iron according to the manufacturer’s directions.
Warm the cheese fondue according to the package directions (alternatively, use one of the fondue recipes in this booklet), and serve warm over the freshly made waffles.