In a medium mixing bowl, whisk together the sourdough discard, milk, egg, and melted butter (or oil). If you prefer a slightly sweeter pancake, whisk in the sugar at this stage.
In a separate small bowl, combine the baking soda and salt. Add this dry mixture to the wet ingredients and whisk gently until just combined. A few lumps are perfectly fine; avoid overmixing.
Heat a lightly oiled griddle or non-stick skillet over medium heat. Once hot, pour about 1/4 cup of batter per pancake onto the griddle.
Cook for 2-3 minutes per side, or until golden brown and cooked through. Bubbles will appear on the surface when the first side is ready to flip.
Serve immediately with your favorite toppings.