Set oven to 350 degrees.
Butter a 8x8-inch baking dish.
Layer HALF of the hash brown potatoes in the bottom of the dish, then sprinkle with black pepper, then HALF of the chopped onion, then HALF of the cooked bacon, then half of the cheddar cheese.
Repeat the layers.
In a small bowl combine the egg with evaporated milk and seasoning salt and pepper; pour evenly over the potato mixture.
Top/sprinkle with grated Parmesan cheese (any amount desired).
Cover with foil and bake for about 45-50 minutes.
Uncover and bake for another 10 minutes (at this point you can sprinkle grated cheddar cheese on top if desired and return to oven).
Let sit for about 10-15 minutes before slicing.