Heat pancake griddle to 375°F. Lightly grease griddle.
Measure Buttermilk Pancake Mix by lightly spooning it into measuring cup and leveling it off.
Whisk mix, salt and pepper until combined. Add water and mix just until combined. Do not over-mix. Gently fold in hash browns, cheese and onions. Let batter stand for 2 minutes.
Pour slightly less than 1/4 cup of batter per pancake onto griddle.
Cook for 1 1/2-2 minutes per side, turning only once. Serve topped with sour cream or salsa, if desired.