Combine flour, salt, and baking soda in a medium bowl. Stir to combine.
Lightly beat the egg in another medium bowl. Add the sugar, butter, and shortening and mix well with an electric mixer until smooth. Add the half-and-half, milk, buttermilk and vanilla. Mix well.
Add the wet mixture to the dry mixture while beating. Mix only briefly. Small lumps are fine, as over beating could produce waffles that are too tough.
Cover and chill overnight if possible.
Rub a light coating of vegetable oil on your waffle iron or use a non-stick oil spray. Preheat the waffle iron. Leave the batter out of the refrigerator to warm up a bit as your waffle iron is preheating.
Spoon ⅓ to ½ cup of batter into the waffle iron and cook for 3 to 4 minutes or until the waffles are brown.
