Preheat the oven to 400°F (200°C). Spread frozen hash browns on a baking sheet, drizzle with olive oil, and season with salt and pepper. Bake for 20 minutes, flipping halfway through, until golden and crispy.

While the hash browns are baking, heat a skillet over medium heat with a splash of olive oil. Cook the chopped bacon for about 6-8 minutes until crispy, then crumble into bite-sized pieces.

In the same skillet, melt a tablespoon of unsalted butter. Crack in the eggs, cooking sunny-side up for 3-4 minutes until the whites are set and yolks remain runny.

Set up a double boiler or a heatproof bowl over simmering water. Whisk together egg yolks, Dijon mustard, and white wine vinegar until it thickens. Gradually add melted butter while whisking until creamy. Squeeze in lemon juice, and add cayenne pepper and garlic powder.

Layer crispy hash browns on a plate. Top with sunny-side-up eggs, crumbled bacon, cheddar, and mozzarella cheese. Drizzle with gravy.

Finally, drizzle hollandaise sauce over the assembled poutine, garnish with fresh herbs if desired, and serve immediately.