Preheat broiler. Heat large skillet (preferably cast iron) over medium high heat. Add olive oil and butter. Pour hash browns into pan and press down. Cook for 5-6 minutes, until golden and crispy. Carefully flip and cook until other side is golden.
Meanwhile, prepare the hollandaise sauce. Vigorously whisk the egg yolks and lemon juice together in a stainless steel bowl until the mixture is thickened and doubled in volume. Place the bowl over a saucepan containing barely simmering water (make sure the water does not touch the bottom of the bowl). Continue to whisk rapidly. Be careful not to let the eggs get too hot or they will scramble. Slowly drizzle in the melted butter and continue to whisk until the sauce is thickened and doubled in volume. Remove from heat and whisk in the salt. Cover and place in a warm spot until ready to use. If the sauce gets too thick, whisk in a few drops of warm water before serving.
Layer the hash browns with bacon, sausage and Canadian bacon. Sprinkle with cheese. Place under broiler until cheese has melted. Meanwhile, cook 4 eggs over easy (or to your preference). Top skillet with eggs and drizzle with desired amount of hollandaise sauce. Cut into wedges and serve.